14201771010119穷吉

实验十四 Swing图形界面组件

理论知识：

模型-视图-控制器设计模式(Model –ViewController )是Java EE平台下创建 Web 应用程序的重要设计模式。

Java组件有内容、外观、行为三个主要元素；这三个主要元素与模型—视图—控制器模式的三部件的对应关系为：内容——控制器（作用：处理用户输入）外观——视图（作用：显示内容）行为——模型（作用：存储内容）

布局管理器是一组类。实现 java.awt.LayoutManager 接口；决定容器中组件的位置和大小

Java.awt包中定义了5种布局管理类，每一种布局管理类对应一种布局策略。每个容器都有与之相关的默认布局管理器。当一个容器选定一种布局策略时，它应该创建该策略对应的布局管理器对象，并将此对象设置为自己的布局管理器。

5种布局管理器：（1）FlowLayout:流布局(Applet和Panel的默认布局管理器）（2）BorderLayout：边框布局( Window、Frame和Dialog的默认布局管理器）（3）GridLayout:网格布局（4）GridBagLayout: 网格组布局（5）CardLayout :卡片布局

FlowLayout Manager 组件采用从左到右，从上到下逐行摆放。

GridBagLayout不需要组件的尺寸一致，容许组件扩展到多行、多列。

每个容器对象在没有设置新的布局前，在容器中添加组件都按照该容器的缺省布局排列。通过setLayout( )方法为容器设置新的布局。格式 : 容器组件名.setLayout( 布局类对象名)

FlowLayout (流布局管理器)：用于对组件逐行地定位，每完成一行，一个新行便又开始。与其他布局管理器不同的是，流布局管理器不限制它所管理组件的大小，允许它们有自己的最佳大小。

文本域(JTextField) : 用于获取单行文本输入。文本域的使用方法：JPanel panel = new JPanel(); JTextField textField = new JTextField("Default input", 20); panel.add(textField);第一个参数“Default input”：将文本域的缺省显示值为Default input ；第二个参数20：表示文本域显示宽度为20列。若要重新设置列数，可使用setColumns方法。

文本输入常用API：用于文本输入的组件继承于JTextComponent抽象类， java.swing.text.JTextComponent 1.2：String getText() ； void setText(String text) 获取或设置文本组件中的文本。 boolean isEditable() ； void setEditable(boolean b) 获取或设置editable特性，这个特性决定了用户是否可以编辑文本组件中的内容。 Java.swing. JComponent ： void revalidate( ) ：重新计算容器内所有组件的大小和位置，并对它们重新布局。如 panel.revalidate()

文本域JTextField常用API ： Java.swing. JTextField： JTextField(int cols) 构造一个指定列数的空JTextField对象。 JTextField(String text，int cols) 构造一个指定列数、指定初始字符串的JTextField对象。 int getColumns(int cols) ； void setColumns(int cols) 获取或设置文本域使用的列数

文本区与文本域的异同相同之处：文本域和文本区组件都可用于获取文本输入。不同之处：文本域只能接受单行文本的输入；文本区能够接受多行文本的输入。

标签是容纳文本的组件。它们没有任何修饰（如没有边界），也不响应用户输入。标签的常用用途之一就是标识组件，例如标识文本域。其使用步骤如下： 1. 创建一个JLabel组件。例： JLabel label = new JLabel(“hours”, SwingConstants.RIGHT); 或者 JLabel label = new JLabel(“hours”, JLabel.RIGHT);以上代码创建了一个label，并指定label的对齐方式为右对齐。 2. 将标签组件放置在距离被标识组件足够近的地方。

密码域是一种特殊类型的文本域。每个输入的字符都用回显字符实现,典型的回显字符为*。

复选框（ JCheckBox ）：如果想要接收的输入只是“是”或“非”，就可以使用复选框组件。用户通过单击某个复选框来选择相应的选项，再点击则取消选择。当复选框获得焦点时，用户也可以通过空格键来切换选择。

复选框常用API: 1.void setSelected(boolean state); 设置复选框的选择状态 2.boolean isSelected(); 获取复选框的选择状态

边框：如果在一个窗口中有多组复选框或单选按钮，就需要可视化的形式指明哪些按钮属于同一组。Swing提供了一组很有用的边框（ borders）来解决这个问题。

边框的创建方法：可以调用BorderFactory类的静态方法创建。可选的风格有：凹斜面：BorderFactory.createLoweredBevelBorder() 凸斜面：BorderFactory.createRaisedBevelBorder() 蚀刻：BorderFactory.createEtchedBorder() 直线：BorderFactory.createLineBorder(Color) 不光滑：BorderFactory.createMatteBorder()还可以给边框加标题 BorderFactory.createTitledBorder()

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1、实验目的与要求

(1) 掌握GUI布局管理器用法；

(2) 掌握各类Java Swing组件用途及常用API；

2、实验内容和步骤

实验1： 导入第12章示例程序，测试程序并进行组内讨论。

测试程序1

l 在elipse IDE中运行教材479页程序12-1，结合运行结果理解程序；

l 掌握各种布局管理器的用法；

l 理解GUI界面中事件处理技术的用途。

l 在布局管理应用代码处添加注释；

1 import java.awt.*;2 import javax.swing.*;3 4 /**5  * @version 1.34 2015-06-126  * @author Cay Horstmann7  */8 public class Calculator9 {
10    public static void main(String[] args)
11    {
12       EventQueue.invokeLater(() -> {
13          CalculatorFrame frame = new CalculatorFrame();
14          frame.setTitle("Calculator");
15          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
16          frame.setVisible(true);
17       });
18    }
19 }

 1 package calculator;2 3 import javax.swing.*;4 5 /**6  * 一个带有计算器面板的框架。7  */8 public class CalculatorFrame extends JFrame9 {
10    public CalculatorFrame()
11    {
12       add(new CalculatorPanel());
13       pack();
14    }
15 }

package calculator.copy;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
* A panel with calculator buttons and a result display.
*/
public class CalculatorPanel extends JPanel
{
private JButton display;
private JPanel panel;
private double result;
private String lastCommand;
private boolean start;

public CalculatorPanel()
{
setLayout(new BorderLayout());

result = 0;
lastCommand = "=";
start = true;

// add the display

display = new JButton("0");
display.setEnabled(false);
add(display, BorderLayout.NORTH);

ActionListener insert = new InsertAction();
ActionListener command = new CommandAction();

// add the buttons in a 4 x 4 grid

panel = new JPanel();
panel.setLayout(new GridLayout(4, 4));

addButton("7", insert);
addButton("8", insert);
addButton("9", insert);
addButton("/", command);

addButton("4", insert);
addButton("5", insert);
addButton("6", insert);
addButton("*", command);

addButton("1", insert);
addButton("2", insert);
addButton("3", insert);
addButton("-", command);

addButton("0", insert);
addButton(".", insert);
addButton("=", command);
addButton("+", command);

add(panel, BorderLayout.CENTER);
}

/**
* Adds a button to the center panel.
* @param label the button label
* @param listener the button listener
*/
private void addButton(String label, ActionListener listener)
{
JButton button = new JButton(label);
button.addActionListener(listener);
panel.add(button);
}

/**
* This action inserts the button action string to the end of the display text.
*/
private class InsertAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
String input = event.getActionCommand();
if (start)
{
display.setText("");
start = false;
}
display.setText(display.getText() + input);
}
}

/**
* This action executes the command that the button action string denotes.
*/
private class CommandAction implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
String command = event.getActionCommand();

if (start)
{
if (command.equals("-"))
{
display.setText(command);
start = false;
}
else lastCommand = command;
}
else
{
calculate(Double.parseDouble(display.getText()));
lastCommand = command;
start = true;
}
}
}

/**
* Carries out the pending calculation.
* @param x the value to be accumulated with the prior result.
*/
public void calculate(double x)
{
if (lastCommand.equals("+")) result += x;
else if (lastCommand.equals("-")) result -= x;
else if (lastCommand.equals("*")) result *= x;
else if (lastCommand.equals("/")) result /= x;
else if (lastCommand.equals("=")) result = x;
display.setText("" + result);
}
}

测试程序2

l 在elipse IDE中调试运行教材486页程序12-2，结合运行结果理解程序；

l 掌握各种文本组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

 package text;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.41 2015-06-128  * @author Cay Horstmann9  */
10 public class TextComponentTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new TextComponentFrame();
16          frame.setTitle("TextComponentTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package text;2 3 import java.awt.BorderLayout;4 import java.awt.GridLayout;5 6 import javax.swing.JButton;7 import javax.swing.JFrame;8 import javax.swing.JLabel;9 import javax.swing.JPanel;
10 import javax.swing.JPasswordField;
11 import javax.swing.JScrollPane;
12 import javax.swing.JTextArea;
13 import javax.swing.JTextField;
14 import javax.swing.SwingConstants;
15
16 /**
17  * 具有文本文本组件的框架.
18  */
19 public class TextComponentFrame extends JFrame
20 {
21    public static final int TEXTAREA_ROWS = 8;
22    public static final int TEXTAREA_COLUMNS = 20;
23
24    public TextComponentFrame()
25    {
26       JTextField textField = new JTextField();
27       JPasswordField passwordField = new JPasswordField();
28
29       JPanel northPanel = new JPanel();
30       northPanel.setLayout(new GridLayout(2, 2));
31       northPanel.add(new JLabel("User name: ", SwingConstants.RIGHT));
32       northPanel.add(textField);
33       northPanel.add(new JLabel("Password: ", SwingConstants.RIGHT));
34       northPanel.add(passwordField);
35
36       add(northPanel, BorderLayout.NORTH);
37
38       JTextArea textArea = new JTextArea(TEXTAREA_ROWS, TEXTAREA_COLUMNS);
39       JScrollPane scrollPane = new JScrollPane(textArea);
40
41       add(scrollPane, BorderLayout.CENTER);
42
43       // 添加按钮将文本追加到文本区域
44
45       JPanel southPanel = new JPanel();
46
47       JButton insertButton = new JButton("Insert");
48       southPanel.add(insertButton);
49       insertButton.addActionListener(event ->
50          textArea.append("User name: " + textField.getText() + " Password: "
51             + new String(passwordField.getPassword()) + "\n"));
52
53       add(southPanel, BorderLayout.SOUTH);
54       pack();
55    }
56 }

测试程序3

l 在elipse IDE中调试运行教材489页程序12-3，结合运行结果理解程序；

l 掌握复选框组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

package checkBox;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2015-06-128  * @author Cay Horstmann9  */
10 public class CheckBoxTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new CheckBoxFrame();
16          frame.setTitle("CheckBoxTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package checkBox;2 3 import java.awt.*;4 import java.awt.event.*;5 import javax.swing.*;6 7 /**8  * 带有样本文本标签的框和用于选择字体的复选框9  * attributes.
10  */
11 public class CheckBoxFrame extends JFrame
12 {
13    private JLabel label;
14    private JCheckBox bold;
15    private JCheckBox italic;
16    private static final int FONTSIZE = 24;
17
18    public CheckBoxFrame()
19    {
20       // 添加示例文本标签
21
22       label = new JLabel("The quick brown fox jumps over the lazy dog.");
23       label.setFont(new Font("Serif", Font.BOLD, FONTSIZE));
24       add(label, BorderLayout.CENTER);
25
26       // 此侦听器设置字体属性
27       // 到复选框状态的标签
28
29       ActionListener listener = event -> {
30          int mode = 0;
31          if (bold.isSelected()) mode += Font.BOLD;
32          if (italic.isSelected()) mode += Font.ITALIC;
33          label.setFont(new Font("Serif", mode, FONTSIZE));
34       };
35
36       // 添加复选框
37
38       JPanel buttonPanel = new JPanel();
39
40       bold = new JCheckBox("Bold");
41       bold.addActionListener(listener);
42       bold.setSelected(true);
43       buttonPanel.add(bold);
44
45       italic = new JCheckBox("Italic");
46       italic.addActionListener(listener);
47       buttonPanel.add(italic);
48
49       add(buttonPanel, BorderLayout.SOUTH);
50       pack();
51    }
52 }

测试程序4

l 在elipse IDE中调试运行教材491页程序12-4，运行结果理解程序；

l 掌握单选按钮组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package radioButton;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2015-06-128  * @author Cay Horstmann9  */
10 public class RadioButtonTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new RadioButtonFrame();
16          frame.setTitle("RadioButtonTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package radioButton;2 3 import java.awt.*;4 import java.awt.event.*;5 import javax.swing.*;6 7 /**8  * 带有样本文本标签和单选按钮以选择字体大小的框架。9  */
10 public class RadioButtonFrame extends JFrame
11 {
12    private JPanel buttonPanel;
13    private ButtonGroup group;
14    private JLabel label;
15    private static final int DEFAULT_SIZE = 36;
16
17    public RadioButtonFrame()
18    {
19       // 添加示例文本标签
20
21       label = new JLabel("The quick brown fox jumps over the lazy dog.");
22       label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
23       add(label, BorderLayout.CENTER);
24
25       // 添加单选按钮
26
27       buttonPanel = new JPanel();
28       group = new ButtonGroup();
29
30       addRadioButton("Small", 8);
31       addRadioButton("Medium", 12);
32       addRadioButton("Large", 18);
33       addRadioButton("Extra large", 36);
34
35       add(buttonPanel, BorderLayout.SOUTH);
36       pack();
37    }
38
39    /**
40     * 添加一个设置示例文本字体大小的单选按钮。
41     * @param 命名按钮上出现的字符串
42     * @param 设置此按钮设置的字体大小
43     */
44    public void addRadioButton(String name, int size)
45    {
46       boolean selected = size == DEFAULT_SIZE;
47       JRadioButton button = new JRadioButton(name, selected);
48       group.add(button);
49       buttonPanel.add(button);
50
51       // 此侦听器设置标签字体大小。
52       ActionListener listener = event -> label.setFont(new Font("Serif", Font.PLAIN, size));
53
54       button.addActionListener(listener);
55    }
56 }

测试程序5

l 在elipse IDE中调试运行教材494页程序12-5，结合运行结果理解程序；

l 掌握边框的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package border;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2015-06-138  * @author Cay Horstmann9  */
10 public class BorderTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new BorderFrame();
16          frame.setTitle("BorderTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package border;2 3 import java.awt.*;4 import javax.swing.*;5 import javax.swing.border.*;6 7 /**8  * 用单选按钮选择边框样式的框架9  */
10 public class BorderFrame extends JFrame
11 {
12    private JPanel demoPanel;
13    private JPanel buttonPanel;
14    private ButtonGroup group;
15
16    public BorderFrame()
17    {
18       demoPanel = new JPanel();
19       buttonPanel = new JPanel();
20       group = new ButtonGroup();
21
22       addRadioButton("Lowered bevel", BorderFactory.createLoweredBevelBorder());
23       addRadioButton("Raised bevel", BorderFactory.createRaisedBevelBorder());
24       addRadioButton("Etched", BorderFactory.createEtchedBorder());
25       addRadioButton("Line", BorderFactory.createLineBorder(Color.BLUE));
26       addRadioButton("Matte", BorderFactory.createMatteBorder(10, 10, 10, 10, Color.BLUE));
27       addRadioButton("Empty", BorderFactory.createEmptyBorder());
28
29       Border etched = BorderFactory.createEtchedBorder();
30       Border titled = BorderFactory.createTitledBorder(etched, "Border types");
31       buttonPanel.setBorder(titled);
32
33       setLayout(new GridLayout(2, 1));
34       add(buttonPanel);
35       add(demoPanel);
36       pack();
37    }
38
39    public void addRadioButton(String buttonName, Border b)
40    {
41       JRadioButton button = new JRadioButton(buttonName);
42       button.addActionListener(event -> demoPanel.setBorder(b));
43       group.add(button);
44       buttonPanel.add(button);
45    }
46 }

测试程序6

l 在elipse IDE中调试运行教材498页程序12-6，结合运行结果理解程序；

l 掌握组合框组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package comboBox;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.35 2015-06-128  * @author Cay Horstmann9  */
10 public class ComboBoxTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new ComboBoxFrame();
16          frame.setTitle("ComboBoxTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package comboBox;2 3 import java.awt.BorderLayout;4 import java.awt.Font;5 6 import javax.swing.JComboBox;7 import javax.swing.JFrame;8 import javax.swing.JLabel;9 import javax.swing.JPanel;
10
11 /**
12  * 具有样本文本标签和选择字体面的组合框的框架。
13  */
14 public class ComboBoxFrame extends JFrame
15 {
16    private JComboBox<String> faceCombo;
17    private JLabel label;
18    private static final int DEFAULT_SIZE = 24;
19
20    public ComboBoxFrame()
21    {
22       // 添加示例文本标签
23
24       label = new JLabel("The quick brown fox jumps over the lazy dog.");
25       label.setFont(new Font("Serif", Font.PLAIN, DEFAULT_SIZE));
26       add(label, BorderLayout.CENTER);
27
28       // 制作组合框并添加面部名称
29
30       faceCombo = new JComboBox<>();
31       faceCombo.addItem("Serif");
32       faceCombo.addItem("SansSerif");
33       faceCombo.addItem("Monospaced");
34       faceCombo.addItem("Dialog");
35       faceCombo.addItem("DialogInput");
36
37       // 组合框侦听器将标签字体更改为选定的面部名称。
38
39       faceCombo.addActionListener(event ->
40          label.setFont(
41             new Font(faceCombo.getItemAt(faceCombo.getSelectedIndex()),
42                Font.PLAIN, DEFAULT_SIZE)));
43
44       // 将组合框添加到框架的南部边界的面板上
45
46       JPanel comboPanel = new JPanel();
47       comboPanel.add(faceCombo);
48       add(comboPanel, BorderLayout.SOUTH);
49       pack();
50    }
51 }

测试程序7

l 在elipse IDE中调试运行教材501页程序12-7，结合运行结果理解程序；

l 掌握滑动条组件的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package slider;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.15 2015-06-128  * @author Cay Horstmann9  */
10 public class SliderTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          SliderFrame frame = new SliderFrame();
16          frame.setTitle("SliderTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

  1 package slider;2 3 import java.awt.*;4 import java.util.*;5 import javax.swing.*;6 import javax.swing.event.*;7 8 /**9  * 一个具有许多滑块和文本字段的滑块值的框架。10  */11 public class SliderFrame extends JFrame12 {13    private JPanel sliderPanel;14    private JTextField textField;15    private ChangeListener listener;16 17    public SliderFrame()18    {19       sliderPanel = new JPanel();20       sliderPanel.setLayout(new GridBagLayout());21 22       // 所有滑块的公用侦听器23       listener = event -> {24          // 当滑块值改变时更新文本字段25          JSlider source = (JSlider) event.getSource();26          textField.setText("" + source.getValue());27       };28 29       // 添加普通滑块30 31       JSlider slider = new JSlider();32       addSlider(slider, "Plain");33 34       // 添加有主和小蜱的滑块35 36       slider = new JSlider();37       slider.setPaintTicks(true);38       slider.setMajorTickSpacing(20);39       slider.setMinorTickSpacing(5);40       addSlider(slider, "Ticks");41 42       // 添加一个滑动到滴答的滑块43       slider = new JSlider();44       slider.setPaintTicks(true);45       slider.setSnapToTicks(true);46       slider.setMajorTickSpacing(20);47       slider.setMinorTickSpacing(5);48       addSlider(slider, "Snap to ticks");49 50       // 添加没有磁道的滑块51 52       slider = new JSlider();53       slider.setPaintTicks(true);54       slider.setMajorTickSpacing(20);55       slider.setMinorTickSpacing(5);56       slider.setPaintTrack(false);57       addSlider(slider, "No track");58 59       // 添加倒置滑块60       slider = new JSlider();61       slider.setPaintTicks(true);62       slider.setMajorTickSpacing(20);63       slider.setMinorTickSpacing(5);64       slider.setInverted(true);65       addSlider(slider, "Inverted");66 67       // 添加带有数字标签的滑块68 69       slider = new JSlider();70       slider.setPaintTicks(true);71       slider.setPaintLabels(true);72       slider.setMajorTickSpacing(20);73       slider.setMinorTickSpacing(5);74       addSlider(slider, "Labels");75 76       // 添加带有字母标签的滑块77       slider = new JSlider();78       slider.setPaintLabels(true);79       slider.setPaintTicks(true);80       slider.setMajorTickSpacing(20);81       slider.setMinorTickSpacing(5);82 83       Dictionary<Integer, Component> labelTable = new Hashtable<>();84       labelTable.put(0, new JLabel("A"));85       labelTable.put(20, new JLabel("B"));86       labelTable.put(40, new JLabel("C"));87       labelTable.put(60, new JLabel("D"));88       labelTable.put(80, new JLabel("E"));89       labelTable.put(100, new JLabel("F"));90 91       slider.setLabelTable(labelTable);92       addSlider(slider, "Custom labels");93 94       // 添加带有图标标签的滑块95 96       slider = new JSlider();97       slider.setPaintTicks(true);98       slider.setPaintLabels(true);99       slider.setSnapToTicks(true);
100       slider.setMajorTickSpacing(20);
101       slider.setMinorTickSpacing(20);
102
103       labelTable = new Hashtable<Integer, Component>();
104
105       // 添加卡片图像
106
107       labelTable.put(0, new JLabel(new ImageIcon("nine.gif")));
108       labelTable.put(20, new JLabel(new ImageIcon("ten.gif")));
109       labelTable.put(40, new JLabel(new ImageIcon("jack.gif")));
110       labelTable.put(60, new JLabel(new ImageIcon("queen.gif")));
111       labelTable.put(80, new JLabel(new ImageIcon("king.gif")));
112       labelTable.put(100, new JLabel(new ImageIcon("ace.gif")));
113
114       slider.setLabelTable(labelTable);
115       addSlider(slider, "Icon labels");
116
117       // 添加显示滑块值的文本字段
118
119       textField = new JTextField();
120       add(sliderPanel, BorderLayout.CENTER);
121       add(textField, BorderLayout.SOUTH);
122       pack();
123    }
124
125    /**
126     * 向滑块面板添加滑块并钩住听者
127     * @param S滑块
128     * @param 描述滑块描述
129     */
130    public void addSlider(JSlider s, String description)
131    {
132       s.addChangeListener(listener);
133       JPanel panel = new JPanel();
134       panel.add(s);
135       panel.add(new JLabel(description));
136       panel.setAlignmentX(Component.LEFT_ALIGNMENT);
137       GridBagConstraints gbc = new GridBagConstraints();
138       gbc.gridy = sliderPanel.getComponentCount();
139       gbc.anchor = GridBagConstraints.WEST;
140       sliderPanel.add(panel, gbc);
141    }
142 }

测试程序8

l 在elipse IDE中调试运行教材512页程序12-8，结合运行结果理解程序；

l 掌握菜单的创建、菜单事件监听器、复选框和单选按钮菜单项、弹出菜单以及快捷键和加速器的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package menu;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.24 2012-06-128  * @author Cay Horstmann9  */
10 public class MenuTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new MenuFrame();
16          frame.setTitle("MenuTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

  1 package menu;2 3 import java.awt.event.*;4 import javax.swing.*;5 6 /**7  * 一个带有示例菜单栏的框架。8  */9 public class MenuFrame extends JFrame10 {11    private static final int DEFAULT_WIDTH = 300;12    private static final int DEFAULT_HEIGHT = 200;13    private Action saveAction;14    private Action saveAsAction;15    private JCheckBoxMenuItem readonlyItem;16    private JPopupMenu popup;17 18    /**19     * 将动作名称打印到Studio.OUT的示例动作。20     */21    class TestAction extends AbstractAction22    {23       public TestAction(String name)24       {25          super(name);26       }27 28       public void actionPerformed(ActionEvent event)29       {30          System.out.println(getValue(Action.NAME) + " selected.");31       }32    }33 34    public MenuFrame()35    {36       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);37 38       JMenu fileMenu = new JMenu("File");39       fileMenu.add(new TestAction("New"));40 41       // 演示加速器42       JMenuItem openItem = fileMenu.add(new TestAction("Open"));43       openItem.setAccelerator(KeyStroke.getKeyStroke("ctrl O"));44 45       fileMenu.addSeparator();46 47       saveAction = new TestAction("Save");48       JMenuItem saveItem = fileMenu.add(saveAction);49       saveItem.setAccelerator(KeyStroke.getKeyStroke("ctrl S"));50 51       saveAsAction = new TestAction("Save As");52       fileMenu.add(saveAsAction);53       fileMenu.addSeparator();54 55       fileMenu.add(new AbstractAction("Exit")56          {57             public void actionPerformed(ActionEvent event)58             {59                System.exit(0);60             }61          });62 63       // 演示复选框和单选按钮菜单64 65       readonlyItem = new JCheckBoxMenuItem("Read-only");66       readonlyItem.addActionListener(new ActionListener()67          {68             public void actionPerformed(ActionEvent event)69             {70                boolean saveOk = !readonlyItem.isSelected();71                saveAction.setEnabled(saveOk);72                saveAsAction.setEnabled(saveOk);73             }74          });75 76       ButtonGroup group = new ButtonGroup();77 78       JRadioButtonMenuItem insertItem = new JRadioButtonMenuItem("Insert");79       insertItem.setSelected(true);80       JRadioButtonMenuItem overtypeItem = new JRadioButtonMenuItem("Overtype");81 82       group.add(insertItem);83       group.add(overtypeItem);84 85       // 演示图标86 87       Action cutAction = new TestAction("Cut");88       cutAction.putValue(Action.SMALL_ICON, new ImageIcon("cut.gif"));89       Action copyAction = new TestAction("Copy");90       copyAction.putValue(Action.SMALL_ICON, new ImageIcon("copy.gif"));91       Action pasteAction = new TestAction("Paste");92       pasteAction.putValue(Action.SMALL_ICON, new ImageIcon("paste.gif"));93 94       JMenu editMenu = new JMenu("Edit");95       editMenu.add(cutAction);96       editMenu.add(copyAction);97       editMenu.add(pasteAction);98 99       // 演示嵌套菜单
100
101       JMenu optionMenu = new JMenu("Options");
102
103       optionMenu.add(readonlyItem);
104       optionMenu.addSeparator();
105       optionMenu.add(insertItem);
106       optionMenu.add(overtypeItem);
107
108       editMenu.addSeparator();
109       editMenu.add(optionMenu);
110
111       // 助记符演示
112
113       JMenu helpMenu = new JMenu("Help");
114       helpMenu.setMnemonic('H');
115
116       JMenuItem indexItem = new JMenuItem("Index");
117       indexItem.setMnemonic('I');
118       helpMenu.add(indexItem);
119
120       // 还可以将助记键添加到动作中。
121       Action aboutAction = new TestAction("About");
122       aboutAction.putValue(Action.MNEMONIC_KEY, new Integer('A'));
123       helpMenu.add(aboutAction);
124
125       // 将所有顶级菜单添加到菜单栏
126
127       JMenuBar menuBar = new JMenuBar();
128       setJMenuBar(menuBar);
129
130       menuBar.add(fileMenu);
131       menuBar.add(editMenu);
132       menuBar.add(helpMenu);
133
134       // 演示弹出窗口
135
136       popup = new JPopupMenu();
137       popup.add(cutAction);
138       popup.add(copyAction);
139       popup.add(pasteAction);
140
141       JPanel panel = new JPanel();
142       panel.setComponentPopupMenu(popup);
143       add(panel);
144    }
145 }

测试程序9

l 在elipse IDE中调试运行教材517页程序12-9，结合运行结果理解程序；

l 掌握工具栏和工具提示的用法；

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package toolBar;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.14 2015-06-128  * @author Cay Horstmann9  */
10 public class ToolBarTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          ToolBarFrame frame = new ToolBarFrame();
16          frame.setTitle("ToolBarTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package toolBar;2 3 import java.awt.*;4 import java.awt.event.*;5 import javax.swing.*;6 7 /**8  * 带有工具栏和菜单的框架，用于颜色变化。9  */
10 public class ToolBarFrame extends JFrame
11 {
12    private static final int DEFAULT_WIDTH = 300;
13    private static final int DEFAULT_HEIGHT = 200;
14    private JPanel panel;
15
16    public ToolBarFrame()
17    {
18       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
19
20       // 添加颜色变化面板
21
22       panel = new JPanel();
23       add(panel, BorderLayout.CENTER);
24
25       // 设置动作
26       Action blueAction = new ColorAction("Blue", new ImageIcon("blue-ball.gif"), Color.BLUE);
27       Action yellowAction = new ColorAction("Yellow", new ImageIcon("yellow-ball.gif"),
28             Color.YELLOW);
29       Action redAction = new ColorAction("Red", new ImageIcon("red-ball.gif"), Color.RED);
30
31       Action exitAction = new AbstractAction("Exit", new ImageIcon("exit.gif"))
32          {
33             public void actionPerformed(ActionEvent event)
34             {
35                System.exit(0);
36             }
37          };
38       exitAction.putValue(Action.SHORT_DESCRIPTION, "Exit");
39
40       // 填充工具栏
41
42       JToolBar bar = new JToolBar();
43       bar.add(blueAction);
44       bar.add(yellowAction);
45       bar.add(redAction);
46       bar.addSeparator();
47       bar.add(exitAction);
48       add(bar, BorderLayout.NORTH);
49
50       // 填充菜单
51
52       JMenu menu = new JMenu("Color");
53       menu.add(yellowAction);
54       menu.add(blueAction);
55       menu.add(redAction);
56       menu.add(exitAction);
57       JMenuBar menuBar = new JMenuBar();
58       menuBar.add(menu);
59       setJMenuBar(menuBar);
60    }
61
62    /**
63     * 颜色动作将帧的背景设置为给定的颜色。
64     */
65    class ColorAction extends AbstractAction
66    {
67       public ColorAction(String name, Icon icon, Color c)
68       {
69          putValue(Action.NAME, name);
70          putValue(Action.SMALL_ICON, icon);
71          putValue(Action.SHORT_DESCRIPTION, name + " background");
72          putValue("Color", c);
73       }
74
75       public void actionPerformed(ActionEvent event)
76       {
77          Color c = (Color) getValue("Color");
78          panel.setBackground(c);
79       }
80    }
81 }

测试程序10

l 在elipse IDE中调试运行教材524页程序12-10、12-11，结合运行结果理解程序，了解GridbagLayout的用法。

1 package gridbag;2 3 import java.awt.EventQueue;4 5 import javax.swing.JFrame;6 7 /**8  * @version 1.35 2015-06-129  * @author Cay Horstmann
10  */
11 public class GridBagLayoutTest
12 {
13    public static void main(String[] args)
14    {
15       EventQueue.invokeLater(() ->           {
16                JFrame frame = new FontFrame();
17                frame.setTitle("GridBagLayoutTest");
18                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
19                frame.setVisible(true);
20          });
21    }
22 }

  1 package gridbag;2 3 import java.awt.*;4 5 /**6  * This class simplifies the use of the GridBagConstraints class.7  * @version 1.01 2004-05-068  * @author Cay Horstmann9  */10 public class GBC extends GridBagConstraints11 {12    /**13     * Constructs a GBC with a given gridx and gridy position and all other grid14     * bag constraint values set to the default.15     * @param gridx the gridx position16     * @param gridy the gridy position17     */18    public GBC(int gridx, int gridy)19    {20       this.gridx = gridx;21       this.gridy = gridy;22    }23 24    /**25     * Constructs a GBC with given gridx, gridy, gridwidth, gridheight and all26     * other grid bag constraint values set to the default.27     * @param gridx the gridx position28     * @param gridy the gridy position29     * @param gridwidth the cell span in x-direction30     * @param gridheight the cell span in y-direction31     */32    public GBC(int gridx, int gridy, int gridwidth, int gridheight)33    {34       this.gridx = gridx;35       this.gridy = gridy;36       this.gridwidth = gridwidth;37       this.gridheight = gridheight;38    }39 40    /**41     * Sets the anchor.42     * @param anchor the anchor value43     * @return this object for further modification44     */45    public GBC setAnchor(int anchor)46    {47       this.anchor = anchor;48       return this;49    }50 51    /**52     * Sets the fill direction.53     * @param fill the fill direction54     * @return this object for further modification55     */56    public GBC setFill(int fill)57    {58       this.fill = fill;59       return this;60    }61 62    /**63     * Sets the cell weights.64     * @param weightx the cell weight in x-direction65     * @param weighty the cell weight in y-direction66     * @return this object for further modification67     */68    public GBC setWeight(double weightx, double weighty)69    {70       this.weightx = weightx;71       this.weighty = weighty;72       return this;73    }74 75    /**76     * Sets the insets of this cell.77     * @param distance the spacing to use in all directions78     * @return this object for further modification79     */80    public GBC setInsets(int distance)81    {82       this.insets = new Insets(distance, distance, distance, distance);83       return this;84    }85 86    /**87     * Sets the insets of this cell.88     * @param top the spacing to use on top89     * @param left the spacing to use to the left90     * @param bottom the spacing to use on the bottom91     * @param right the spacing to use to the right92     * @return this object for further modification93     */94    public GBC setInsets(int top, int left, int bottom, int right)95    {96       this.insets = new Insets(top, left, bottom, right);97       return this;98    }99
100    /**
101     * Sets the internal padding
102     * @param ipadx the internal padding in x-direction
103     * @param ipady the internal padding in y-direction
104     * @return this object for further modification
105     */
106    public GBC setIpad(int ipadx, int ipady)
107    {
108       this.ipadx = ipadx;
109       this.ipady = ipady;
110       return this;
111    }
112 }

 1 package gridbag;2 3 import java.awt.Font;4 import java.awt.GridBagLayout;5 import java.awt.event.ActionListener;6 7 import javax.swing.BorderFactory;8 import javax.swing.JCheckBox;9 import javax.swing.JComboBox;
10 import javax.swing.JFrame;
11 import javax.swing.JLabel;
12 import javax.swing.JTextArea;
13
14 /**
15  * A frame that uses a grid bag layout to arrange font selection components.
16  */
17 public class FontFrame extends JFrame
18 {
19    public static final int TEXT_ROWS = 10;
20    public static final int TEXT_COLUMNS = 20;
21
22    private JComboBox<String> face;
23    private JComboBox<Integer> size;
24    private JCheckBox bold;
25    private JCheckBox italic;
26    private JTextArea sample;
27
28    public FontFrame()
29    {
30       GridBagLayout layout = new GridBagLayout();
31       setLayout(layout);
32
33       ActionListener listener = event -> updateSample();
34
35       // construct components
36
37       JLabel faceLabel = new JLabel("Face: ");
38
39       face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced",
40             "Dialog", "DialogInput" });
41
42       face.addActionListener(listener);
43
44       JLabel sizeLabel = new JLabel("Size: ");
45
46       size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });
47
48       size.addActionListener(listener);
49
50       bold = new JCheckBox("Bold");
51       bold.addActionListener(listener);
52
53       italic = new JCheckBox("Italic");
54       italic.addActionListener(listener);
55
56       sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
57       sample.setText("The quick brown fox jumps over the lazy dog");
58       sample.setEditable(false);
59       sample.setLineWrap(true);
60       sample.setBorder(BorderFactory.createEtchedBorder());
61
62       // add components to grid, using GBC convenience class
63
64       add(faceLabel, new GBC(0, 0).setAnchor(GBC.EAST));
65       add(face, new GBC(1, 0).setFill(GBC.HORIZONTAL).setWeight(100, 0)
66             .setInsets(1));
67       add(sizeLabel, new GBC(0, 1).setAnchor(GBC.EAST));
68       add(size, new GBC(1, 1).setFill(GBC.HORIZONTAL).setWeight(100, 0)
69             .setInsets(1));
70       add(bold, new GBC(0, 2, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
71       add(italic, new GBC(0, 3, 2, 1).setAnchor(GBC.CENTER).setWeight(100, 100));
72       add(sample, new GBC(2, 0, 1, 4).setFill(GBC.BOTH).setWeight(100, 100));
73       pack();
74       updateSample();
75    }
76
77    public void updateSample()
78    {
79       String fontFace = (String) face.getSelectedItem();
80       int fontStyle = (bold.isSelected() ? Font.BOLD : 0)
81             + (italic.isSelected() ? Font.ITALIC : 0);
82       int fontSize = size.getItemAt(size.getSelectedIndex());
83       Font font = new Font(fontFace, fontStyle, fontSize);
84       sample.setFont(font);
85       sample.repaint();
86    }
87 }

l 在elipse IDE中调试运行教材533页程序12-12，结合程序运行结果理解程序，了解GroupLayout的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package groupLayout;2 3 import java.awt.EventQueue;4 5 import javax.swing.JFrame;6 7 /**8  * @version 1.01 2015-06-129  * @author Cay Horstmann
10  */
11 public class GroupLayoutTest
12 {
13    public static void main(String[] args)
14    {
15       EventQueue.invokeLater(() -> {
16          JFrame frame = new FontFrame();
17          frame.setTitle("GroupLayoutTest");
18          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
19          frame.setVisible(true);
20       });
21    }
22 }

  1 package groupLayout;2 3 import java.awt.Font;4 import java.awt.event.ActionListener;5 6 import javax.swing.BorderFactory;7 import javax.swing.GroupLayout;8 import javax.swing.JCheckBox;9 import javax.swing.JComboBox;10 import javax.swing.JFrame;11 import javax.swing.JLabel;12 import javax.swing.JScrollPane;13 import javax.swing.JTextArea;14 import javax.swing.LayoutStyle;15 import javax.swing.SwingConstants;16 17 /**18  * A frame that uses a group layout to arrange font selection components.19  */20 public class FontFrame extends JFrame21 {22    public static final int TEXT_ROWS = 10;23    public static final int TEXT_COLUMNS = 20;24 25    private JComboBox<String> face;26    private JComboBox<Integer> size;27    private JCheckBox bold;28    private JCheckBox italic;29    private JScrollPane pane;30    private JTextArea sample;31 32    public FontFrame()33    {34       ActionListener listener = event -> updateSample(); 35 36       // construct components37 38       JLabel faceLabel = new JLabel("Face: ");39 40       face = new JComboBox<>(new String[] { "Serif", "SansSerif", "Monospaced", "Dialog",41             "DialogInput" });42 43       face.addActionListener(listener);44 45       JLabel sizeLabel = new JLabel("Size: ");46 47       size = new JComboBox<>(new Integer[] { 8, 10, 12, 15, 18, 24, 36, 48 });48 49       size.addActionListener(listener);50 51       bold = new JCheckBox("Bold");52       bold.addActionListener(listener);53 54       italic = new JCheckBox("Italic");55       italic.addActionListener(listener);56 57       sample = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);58       sample.setText("The quick brown fox jumps over the lazy dog");59       sample.setEditable(false);60       sample.setLineWrap(true);61       sample.setBorder(BorderFactory.createEtchedBorder());62 63       pane = new JScrollPane(sample);64 65       GroupLayout layout = new GroupLayout(getContentPane());66       setLayout(layout);67       layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)68             .addGroup(69                   layout.createSequentialGroup().addContainerGap().addGroup(70                         layout.createParallelGroup(GroupLayout.Alignment.LEADING).addGroup(71                               GroupLayout.Alignment.TRAILING,72                               layout.createSequentialGroup().addGroup(73                                     layout.createParallelGroup(GroupLayout.Alignment.TRAILING)74                                           .addComponent(faceLabel).addComponent(sizeLabel))75                                     .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)76                                     .addGroup(77                                           layout.createParallelGroup(78                                                 GroupLayout.Alignment.LEADING, false)79                                                 .addComponent(size).addComponent(face)))80                               .addComponent(italic).addComponent(bold)).addPreferredGap(81                         LayoutStyle.ComponentPlacement.RELATED).addComponent(pane)82                         .addContainerGap()));83 84       layout.linkSize(SwingConstants.HORIZONTAL, new java.awt.Component[] { face, size });85 86       layout.setVerticalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)87             .addGroup(88                   layout.createSequentialGroup().addContainerGap().addGroup(89                         layout.createParallelGroup(GroupLayout.Alignment.LEADING).addComponent(90                               pane, GroupLayout.Alignment.TRAILING).addGroup(91                               layout.createSequentialGroup().addGroup(92                                     layout.createParallelGroup(GroupLayout.Alignment.BASELINE)93                                           .addComponent(face).addComponent(faceLabel))94                                     .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)95                                     .addGroup(96                                           layout.createParallelGroup(97                                                 GroupLayout.Alignment.BASELINE).addComponent(size)98                                                 .addComponent(sizeLabel)).addPreferredGap(99                                           LayoutStyle.ComponentPlacement.RELATED).addComponent(
100                                           italic, GroupLayout.DEFAULT_SIZE,
101                                           GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
102                                     .addPreferredGap(LayoutStyle.ComponentPlacement.RELATED)
103                                     .addComponent(bold, GroupLayout.DEFAULT_SIZE,
104                                           GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
105                         .addContainerGap()));
106       pack();
107    }
108
109    public void updateSample()
110    {
111       String fontFace = (String) face.getSelectedItem();
112       int fontStyle = (bold.isSelected() ? Font.BOLD : 0)
113             + (italic.isSelected() ? Font.ITALIC : 0);
114       int fontSize = size.getItemAt(size.getSelectedIndex());
115       Font font = new Font(fontFace, fontStyle, fontSize);
116       sample.setFont(font);
117       sample.repaint();
118    }
119 }

测试程序11

l 在elipse IDE中调试运行教材539页程序12-13、12-14，结合运行结果理解程序；

l 掌握定制布局管理器的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package circleLayout;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.33 2015-06-128  * @author Cay Horstmann9  */
10 public class CircleLayoutTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new CircleLayoutFrame();
16          frame.setTitle("CircleLayoutTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package circleLayout;2 3 import javax.swing.*;4 5 /**6  * A frame that shows buttons arranged along a circle.7  */8 public class CircleLayoutFrame extends JFrame9 {
10    public CircleLayoutFrame()
11    {
12       setLayout(new CircleLayout());
13       add(new JButton("Yellow"));
14       add(new JButton("Blue"));
15       add(new JButton("Red"));
16       add(new JButton("Green"));
17       add(new JButton("Orange"));
18       add(new JButton("Fuchsia"));
19       add(new JButton("Indigo"));
20       pack();
21    }
22 }

  1 package circleLayout;2 3 import java.awt.*;4 5 /**6  * A layout manager that lays out components along a circle.7  */8 public class CircleLayout implements LayoutManager9 {10    private int minWidth = 0;11    private int minHeight = 0;12    private int preferredWidth = 0;13    private int preferredHeight = 0;14    private boolean sizesSet = false;15    private int maxComponentWidth = 0;16    private int maxComponentHeight = 0;17 18    public void addLayoutComponent(String name, Component comp)19    {20    }21 22    public void removeLayoutComponent(Component comp)23    {24    }25 26    public void setSizes(Container parent)27    {28       if (sizesSet) return;29       int n = parent.getComponentCount();30 31       preferredWidth = 0;32       preferredHeight = 0;33       minWidth = 0;34       minHeight = 0;35       maxComponentWidth = 0;36       maxComponentHeight = 0;37 38       // compute the maximum component widths and heights39       // and set the preferred size to the sum of the component sizes.40       for (int i = 0; i < n; i++)41       {42          Component c = parent.getComponent(i);43          if (c.isVisible())44          {45             Dimension d = c.getPreferredSize();46             maxComponentWidth = Math.max(maxComponentWidth, d.width);47             maxComponentHeight = Math.max(maxComponentHeight, d.height);48             preferredWidth += d.width;49             preferredHeight += d.height;50          }51       }52       minWidth = preferredWidth / 2;53       minHeight = preferredHeight / 2;54       sizesSet = true;55    }56 57    public Dimension preferredLayoutSize(Container parent)58    {59       setSizes(parent);60       Insets insets = parent.getInsets();61       int width = preferredWidth + insets.left + insets.right;62       int height = preferredHeight + insets.top + insets.bottom;63       return new Dimension(width, height);64    }65 66    public Dimension minimumLayoutSize(Container parent)67    {68       setSizes(parent);69       Insets insets = parent.getInsets();70       int width = minWidth + insets.left + insets.right;71       int height = minHeight + insets.top + insets.bottom;72       return new Dimension(width, height);73    }74 75    public void layoutContainer(Container parent)76    {77       setSizes(parent);78 79       // compute center of the circle80 81       Insets insets = parent.getInsets();82       int containerWidth = parent.getSize().width - insets.left - insets.right;83       int containerHeight = parent.getSize().height - insets.top - insets.bottom;84 85       int xcenter = insets.left + containerWidth / 2;86       int ycenter = insets.top + containerHeight / 2;87 88       // compute radius of the circle89 90       int xradius = (containerWidth - maxComponentWidth) / 2;91       int yradius = (containerHeight - maxComponentHeight) / 2;92       int radius = Math.min(xradius, yradius);93 94       // lay out components along the circle95 96       int n = parent.getComponentCount();97       for (int i = 0; i < n; i++)98       {99          Component c = parent.getComponent(i);
100          if (c.isVisible())
101          {
102             double angle = 2 * Math.PI * i / n;
103
104             // center point of component
105             int x = xcenter + (int) (Math.cos(angle) * radius);
106             int y = ycenter + (int) (Math.sin(angle) * radius);
107
108             // move component so that its center is (x, y)
109             // and its size is its preferred size
110             Dimension d = c.getPreferredSize();
111             c.setBounds(x - d.width / 2, y - d.height / 2, d.width, d.height);
112          }
113       }
114    }
115 }

测试程序12

l 在elipse IDE中调试运行教材544页程序12-15、12-16，结合运行结果理解程序；

l 掌握选项对话框的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

1 package optionDialog;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2015-06-128  * @author Cay Horstmann9  */
10 public class OptionDialogTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new OptionDialogFrame();
16          frame.setTitle("OptionDialogTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package optionDialog;2 3 import javax.swing.*;4 5 /**6  * A panel with radio buttons inside a titled border.7  */8 public class ButtonPanel extends JPanel9 {
10    private ButtonGroup group;
11
12    /**
13     * Constructs a button panel.
14     * @param title the title shown in the border
15     * @param options an array of radio button labels
16     */
17    public ButtonPanel(String title, String... options)
18    {
19       setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), title));
20       setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
21       group = new ButtonGroup();
22
23       // make one radio button for each option
24       for (String option : options)
25       {
26          JRadioButton b = new JRadioButton(option);
27          b.setActionCommand(option);
28          add(b);
29          group.add(b);
30          b.setSelected(option == options[0]);
31       }
32    }
33
34    /**
35     * Gets the currently selected option.
36     * @return the label of the currently selected radio button.
37     */
38    public String getSelection()
39    {
40       return group.getSelection().getActionCommand();
41    }
42 }

  1 package optionDialog;2 3 import java.awt.*;4 import java.awt.event.*;5 import java.awt.geom.*;6 import java.util.*;7 import javax.swing.*;8 9 /**10  * A frame that contains settings for selecting various option dialogs.11  */12 public class OptionDialogFrame extends JFrame13 {14    private ButtonPanel typePanel;15    private ButtonPanel messagePanel;16    private ButtonPanel messageTypePanel;17    private ButtonPanel optionTypePanel;18    private ButtonPanel optionsPanel;19    private ButtonPanel inputPanel;20    private String messageString = "Message";21    private Icon messageIcon = new ImageIcon("blue-ball.gif");22    private Object messageObject = new Date();23    private Component messageComponent = new SampleComponent();24 25    public OptionDialogFrame()26    {27       JPanel gridPanel = new JPanel();28       gridPanel.setLayout(new GridLayout(2, 3));29 30       typePanel = new ButtonPanel("Type", "Message", "Confirm", "Option", "Input");31       messageTypePanel = new ButtonPanel("Message Type", "ERROR_MESSAGE", "INFORMATION_MESSAGE",32             "WARNING_MESSAGE", "QUESTION_MESSAGE", "PLAIN_MESSAGE");33       messagePanel = new ButtonPanel("Message", "String", "Icon", "Component", "Other", 34             "Object[]");35       optionTypePanel = new ButtonPanel("Confirm", "DEFAULT_OPTION", "YES_NO_OPTION",36             "YES_NO_CANCEL_OPTION", "OK_CANCEL_OPTION");37       optionsPanel = new ButtonPanel("Option", "String[]", "Icon[]", "Object[]");38       inputPanel = new ButtonPanel("Input", "Text field", "Combo box");39 40       gridPanel.add(typePanel);41       gridPanel.add(messageTypePanel);42       gridPanel.add(messagePanel);43       gridPanel.add(optionTypePanel);44       gridPanel.add(optionsPanel);45       gridPanel.add(inputPanel);46 47       // add a panel with a Show button48 49       JPanel showPanel = new JPanel();50       JButton showButton = new JButton("Show");51       showButton.addActionListener(new ShowAction());52       showPanel.add(showButton);53 54       add(gridPanel, BorderLayout.CENTER);55       add(showPanel, BorderLayout.SOUTH);56       pack();57    }58 59    /**60     * Gets the currently selected message.61     * @return a string, icon, component, or object array, depending on the Message panel selection62     */63    public Object getMessage()64    {65       String s = messagePanel.getSelection();66       if (s.equals("String")) return messageString;67       else if (s.equals("Icon")) return messageIcon;68       else if (s.equals("Component")) return messageComponent;69       else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,70             messageComponent, messageObject };71       else if (s.equals("Other")) return messageObject;72       else return null;73    }74 75    /**76     * Gets the currently selected options.77     * @return an array of strings, icons, or objects, depending on the Option panel selection78     */79    public Object[] getOptions()80    {81       String s = optionsPanel.getSelection();82       if (s.equals("String[]")) return new String[] { "Yellow", "Blue", "Red" };83       else if (s.equals("Icon[]")) return new Icon[] { new ImageIcon("yellow-ball.gif"),84             new ImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") };85       else if (s.equals("Object[]")) return new Object[] { messageString, messageIcon,86             messageComponent, messageObject };87       else return null;88    }89 90    /**91     * Gets the selected message or option type92     * @param panel the Message Type or Confirm panel93     * @return the selected XXX_MESSAGE or XXX_OPTION constant from the JOptionPane class94     */95    public int getType(ButtonPanel panel)96    {97       String s = panel.getSelection();98       try99       {
100          return JOptionPane.class.getField(s).getInt(null);
101       }
102       catch (Exception e)
103       {
104          return -1;
105       }
106    }
107
108    /**
109     * The action listener for the Show button shows a Confirm, Input, Message, or Option dialog
110     * depending on the Type panel selection.
111     */
112    private class ShowAction implements ActionListener
113    {
114       public void actionPerformed(ActionEvent event)
115       {
116          if (typePanel.getSelection().equals("Confirm")) JOptionPane.showConfirmDialog(
117                OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
118                getType(messageTypePanel));
119          else if (typePanel.getSelection().equals("Input"))
120          {
121             if (inputPanel.getSelection().equals("Text field")) JOptionPane.showInputDialog(
122                   OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
123             else JOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(), "Title",
124                   getType(messageTypePanel), null, new String[] { "Yellow", "Blue", "Red" },
125                   "Blue");
126          }
127          else if (typePanel.getSelection().equals("Message")) JOptionPane.showMessageDialog(
128                OptionDialogFrame.this, getMessage(), "Title", getType(messageTypePanel));
129          else if (typePanel.getSelection().equals("Option")) JOptionPane.showOptionDialog(
130                OptionDialogFrame.this, getMessage(), "Title", getType(optionTypePanel),
131                getType(messageTypePanel), null, getOptions(), getOptions()[0]);
132       }
133    }
134 }
135
136 /**
137  * A component with a painted surface
138  */
139
140 class SampleComponent extends JComponent
141 {
142    public void paintComponent(Graphics g)
143    {
144       Graphics2D g2 = (Graphics2D) g;
145       Rectangle2D rect = new Rectangle2D.Double(0, 0, getWidth() - 1, getHeight() - 1);
146       g2.setPaint(Color.YELLOW);
147       g2.fill(rect);
148       g2.setPaint(Color.BLUE);
149       g2.draw(rect);
150    }
151
152    public Dimension getPreferredSize()
153    {
154       return new Dimension(10, 10);
155    }
156 }

测试程序13

l 在elipse IDE中调试运行教材552页程序12-17、12-18，结合运行结果理解程序；

l 掌握对话框的创建方法；

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package dialog;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2012-06-128  * @author Cay Horstmann9  */
10 public class DialogTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new DialogFrame();
16          frame.setTitle("DialogTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

package dialog;

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

/**
* A frame with a menu whose File->About action shows a dialog.
*/
public class DialogFrame extends JFrame
{
   private static final int DEFAULT_WIDTH = 300;
   private static final int DEFAULT_HEIGHT = 200;
   private AboutDialog dialog;

public DialogFrame()
{
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

// Construct a File menu.

JMenuBar menuBar = new JMenuBar();//菜单栏的实现
      setJMenuBar(menuBar);//设置此窗体的菜单栏
      JMenu fileMenu = new JMenu("File");//菜单的该实现是一个包含 JMenuItem 的弹出窗口，用户选择 JMenuBar 上的项时会显示该 JMenuItem。
      menuBar.add(fileMenu);//将指定的菜单追加到菜单栏的末尾

// Add About and Exit menu items.

// The About item shows the About dialog.

JMenuItem aboutItem = new JMenuItem("About");//菜单中的项的实现
      aboutItem.addActionListener(event -> {
         if (dialog == null) // first time
            dialog = new AboutDialog(DialogFrame.this);
         dialog.setVisible(true); // 设置是否可见
      });
      fileMenu.add(aboutItem);//将某个菜单项追加到此菜单的末尾。返回添加的菜单项

// The Exit item exits the program.

JMenuItem exitItem = new JMenuItem("Exit");
      exitItem.addActionListener(event -> System.exit(0));
      fileMenu.add(exitItem);
   }
}

 1 package dialog;2 3 import java.awt.BorderLayout;4 5 import javax.swing.JButton;6 import javax.swing.JDialog;7 import javax.swing.JFrame;8 import javax.swing.JLabel;9 import javax.swing.JPanel;
10
11 /**
12  * A sample modal dialog that displays a message and waits for the user to click the OK button.
13  */
14 public class AboutDialog extends JDialog
15 {//创建一个具有指定标题，所有者Farmer和模式的对话框。如果owner为null，则一个共享的，隐藏的窗体将设置为该对话框的所有者。
16    public AboutDialog(JFrame owner)
17    {
18       super(owner, "About DialogTest", true);
19
20       // add HTML label to center//将指定的组件添加到此内容的尾部
21
22       add(
23             new JLabel(
24                   "<html><h1><i>Core Java</i></h1><hr>By Cay Horstmann</html>"),
25             BorderLayout.CENTER);
26
27       // OK button closes the dialog
28
29       JButton ok = new JButton("OK");//创建一个新的按钮
30       ok.addActionListener(event -> setVisible(false));
31
32       // add OK button to southern border
33
34       JPanel panel = new JPanel();
35       panel.add(ok);
36       add(panel, BorderLayout.SOUTH);//边框布局，显示在下边
37
38       pack();
39    }
40 }

测试程序14

l 在elipse IDE中调试运行教材556页程序12-19、12-20，结合运行结果理解程序；

l 掌握对话框的数据交换用法;

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package dataExchange;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.34 2015-06-128  * @author Cay Horstmann9  */
10 public class DataExchangeTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new DataExchangeFrame();
16          frame.setTitle("DataExchangeTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package dataExchange;2 3 import java.awt.*;4 import java.awt.event.*;5 import javax.swing.*;6 7 /**8  * A frame with a menu whose File->Connect action shows a password dialog.9  */
10 public class DataExchangeFrame extends JFrame
11 {
12    public static final int TEXT_ROWS = 20;
13    public static final int TEXT_COLUMNS = 40;
14    private PasswordChooser dialog = null;
15    private JTextArea textArea;
16
17    public DataExchangeFrame()
18    {
19       // construct a File menu
20
21       JMenuBar mbar = new JMenuBar();
22       setJMenuBar(mbar);
23       JMenu fileMenu = new JMenu("File");
24       mbar.add(fileMenu);
25
26       // add Connect and Exit menu items
27
28       JMenuItem connectItem = new JMenuItem("Connect");
29       connectItem.addActionListener(new ConnectAction());
30       fileMenu.add(connectItem);
31
32       // The Exit item exits the program
33
34       JMenuItem exitItem = new JMenuItem("Exit");
35       exitItem.addActionListener(event -> System.exit(0));
36       fileMenu.add(exitItem);
37
38       textArea = new JTextArea(TEXT_ROWS, TEXT_COLUMNS);
39       add(new JScrollPane(textArea), BorderLayout.CENTER);
40       pack();
41    }
42
43    /**
44     * The Connect action pops up the password dialog.
45     */
46    private class ConnectAction implements ActionListener
47    {
48       public void actionPerformed(ActionEvent event)
49       {
50          // if first time, construct dialog
51
52          if (dialog == null) dialog = new PasswordChooser();
53
54          // set default values
55          dialog.setUser(new User("yourname", null));
56
57          // pop up dialog
58          if (dialog.showDialog(DataExchangeFrame.this, "Connect"))
59          {
60             // if accepted, retrieve user input
61             User u = dialog.getUser();
62             textArea.append("user name = " + u.getName() + ", password = "
63                   + (new String(u.getPassword())) + "\n");
64          }
65       }
66    }
67 }

  1 package dataExchange;2 3 import java.awt.BorderLayout;4 import java.awt.Component;5 import java.awt.Frame;6 import java.awt.GridLayout;7 8 import javax.swing.JButton;9 import javax.swing.JDialog;10 import javax.swing.JLabel;11 import javax.swing.JPanel;12 import javax.swing.JPasswordField;13 import javax.swing.JTextField;14 import javax.swing.SwingUtilities;15 16 /**17  * A password chooser that is shown inside a dialog18  */19 public class PasswordChooser extends JPanel20 {21    private JTextField username;22    private JPasswordField password;23    private JButton okButton;24    private boolean ok;25    private JDialog dialog;26 27    public PasswordChooser()28    {29       setLayout(new BorderLayout());30 31       // construct a panel with user name and password fields32 33       JPanel panel = new JPanel();34       panel.setLayout(new GridLayout(2, 2));35       panel.add(new JLabel("User name:"));36       panel.add(username = new JTextField(""));37       panel.add(new JLabel("Password:"));38       panel.add(password = new JPasswordField(""));39       add(panel, BorderLayout.CENTER);40 41       // create Ok and Cancel buttons that terminate the dialog42 43       okButton = new JButton("Ok");44       okButton.addActionListener(event -> {45          ok = true;46          dialog.setVisible(false);47       });48 49       JButton cancelButton = new JButton("Cancel");50       cancelButton.addActionListener(event -> dialog.setVisible(false));51 52       // add buttons to southern border53 54       JPanel buttonPanel = new JPanel();55       buttonPanel.add(okButton);56       buttonPanel.add(cancelButton);57       add(buttonPanel, BorderLayout.SOUTH);58    }59 60    /**61     * Sets the dialog defaults.62     * @param u the default user information63     */64    public void setUser(User u)65    {66       username.setText(u.getName());67    }68 69    /**70     * Gets the dialog entries.71     * @return a User object whose state represents the dialog entries72     */73    public User getUser()74    {75       return new User(username.getText(), password.getPassword());76    }77 78    /**79     * Show the chooser panel in a dialog80     * @param parent a component in the owner frame or null81     * @param title the dialog window title82     */83    public boolean showDialog(Component parent, String title)84    {85       ok = false;86 87       // locate the owner frame88 89       Frame owner = null;90       if (parent instanceof Frame)91          owner = (Frame) parent;92       else93          owner = (Frame) SwingUtilities.getAncestorOfClass(Frame.class, parent);94 95       // if first time, or if owner has changed, make new dialog96 97       if (dialog == null || dialog.getOwner() != owner)98       {99          dialog = new JDialog(owner, true);
100          dialog.add(this);
101          dialog.getRootPane().setDefaultButton(okButton);
102          dialog.pack();
103       }
104
105       // set title and show dialog
106
107       dialog.setTitle(title);
108       dialog.setVisible(true);
109       return ok;
110    }
111 }

 1 package dataExchange;2 3 /**4  * A user has a name and password. For security reasons, the password is stored as a char[], not a5  * String.6  */7 public class User8 {9    private String name;
10    private char[] password;
11
12    public User(String aName, char[] aPassword)
13    {
14       name = aName;
15       password = aPassword;
16    }
17
18    public String getName()
19    {
20       return name;
21    }
22
23    public char[] getPassword()
24    {
25       return password;
26    }
27
28    public void setName(String aName)
29    {
30       name = aName;
31    }
32
33    public void setPassword(char[] aPassword)
34    {
35       password = aPassword;
36    }
37 }

测试程序15

l 在elipse IDE中调试运行教材556页程序12-21、12-2212-23，结合程序运行结果理解程序；

l 掌握文件对话框的用法;

l 记录示例代码阅读理解中存在的问题与疑惑。

package fileChooser;import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.*;
import javax.swing.filechooser.FileFilter;/*** A file view that displays an icon for all files that match a file filter.*/
public class FileIconView extends FileView {private FileFilter filter;private Icon icon;/*** Constructs a FileIconView.* * @param aFilter a file filter--all files that this filter accepts will be*                shown with the icon.* @param         anIcon--the icon shown with all accepted files.*/public FileIconView(FileFilter aFilter, Icon anIcon) {filter = aFilter;icon = anIcon;}public Icon getIcon(File f) {if (!f.isDirectory() && filter.accept(f))return icon;elsereturn null;}
}

package fileChooser;import java.awt.*;
import java.io.*;import javax.swing.*;/*** A file chooser accessory that previews images.*/
public class ImagePreviewer extends JLabel {/*** Constructs an ImagePreviewer.* * @param chooser the file chooser whose property changes trigger an image*                change in this previewer*/public ImagePreviewer(JFileChooser chooser) {setPreferredSize(new Dimension(100, 100));setBorder(BorderFactory.createEtchedBorder());chooser.addPropertyChangeListener(event -> {if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY) {// the user has selected a new fileFile f = (File) event.getNewValue();if (f == null) {setIcon(null);return;}// read the image into an iconImageIcon icon = new ImageIcon(f.getPath());// if the icon is too large to fit, scale itif (icon.getIconWidth() > getWidth())icon = new ImageIcon(icon.getImage().getScaledInstance(getWidth(), -1, Image.SCALE_DEFAULT));setIcon(icon);}});}
}

package fileChooser;import java.io.*;import javax.swing.*;
import javax.swing.filechooser.*;
import javax.swing.filechooser.FileFilter;/*** A frame that has a menu for loading an image and a display area for the* loaded image.*/
public class ImageViewerFrame extends JFrame {private static final int DEFAULT_WIDTH = 300;private static final int DEFAULT_HEIGHT = 400;private JLabel label;private JFileChooser chooser;public ImageViewerFrame() {setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);// set up menu barJMenuBar menuBar = new JMenuBar();setJMenuBar(menuBar);JMenu menu = new JMenu("File");menuBar.add(menu);JMenuItem openItem = new JMenuItem("Open");menu.add(openItem);openItem.addActionListener(event -> {chooser.setCurrentDirectory(new File("."));// show file chooser dialogint result = chooser.showOpenDialog(ImageViewerFrame.this);// if image file accepted, set it as icon of the labelif (result == JFileChooser.APPROVE_OPTION) {String name = chooser.getSelectedFile().getPath();label.setIcon(new ImageIcon(name));pack();}});JMenuItem exitItem = new JMenuItem("Exit");menu.add(exitItem);exitItem.addActionListener(event -> System.exit(0));// use a label to display the imageslabel = new JLabel();add(label);// set up file chooserchooser = new JFileChooser();// accept all image files ending with .jpg, .jpeg, .gifFileFilter filter = new FileNameExtensionFilter("Image files", "jpg", "jpeg", "gif");chooser.setFileFilter(filter);chooser.setAccessory(new ImagePreviewer(chooser));chooser.setFileView(new FileIconView(filter, new ImageIcon("palette.gif")));}
}

测试程序16

l 在elipse IDE中调试运行教材570页程序12-24，结合运行结果理解程序；

l 了解颜色选择器的用法。

l 记录示例代码阅读理解中存在的问题与疑惑。

 1 package colorChooser;2 3 import java.awt.*;4 import javax.swing.*;5 6 /**7  * @version 1.04 2015-06-128  * @author Cay Horstmann9  */
10 public class ColorChooserTest
11 {
12    public static void main(String[] args)
13    {
14       EventQueue.invokeLater(() -> {
15          JFrame frame = new ColorChooserFrame();
16          frame.setTitle("ColorChooserTest");
17          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
18          frame.setVisible(true);
19       });
20    }
21 }

 1 package colorChooser;2 3 import java.awt.Color;4 import java.awt.Frame;5 import java.awt.event.ActionEvent;6 import java.awt.event.ActionListener;7 8 import javax.swing.JButton;9 import javax.swing.JColorChooser;
10 import javax.swing.JDialog;
11 import javax.swing.JPanel;
12
13 /**
14  * A panel with buttons to pop up three types of color choosers
15  */
16 public class ColorChooserPanel extends JPanel
17 {
18    public ColorChooserPanel()
19    {
20       JButton modalButton = new JButton("Modal");
21       modalButton.addActionListener(new ModalListener());
22       add(modalButton);
23
24       JButton modelessButton = new JButton("Modeless");
25       modelessButton.addActionListener(new ModelessListener());
26       add(modelessButton);
27
28       JButton immediateButton = new JButton("Immediate");
29       immediateButton.addActionListener(new ImmediateListener());
30       add(immediateButton);
31    }
32
33    /**
34     * This listener pops up a modal color chooser
35     */
36    private class ModalListener implements ActionListener
37    {
38       public void actionPerformed(ActionEvent event)
39       {
40          Color defaultColor = getBackground();
41          Color selected = JColorChooser.showDialog(ColorChooserPanel.this, "Set background",
42                defaultColor);
43          if (selected != null) setBackground(selected);
44       }
45    }
46
47    /**
48     * This listener pops up a modeless color chooser. The panel color is changed when the user
49     * clicks the OK button.
50     */
51    private class ModelessListener implements ActionListener
52    {
53       private JDialog dialog;
54       private JColorChooser chooser;
55
56       public ModelessListener()
57       {
58          chooser = new JColorChooser();
59          dialog = JColorChooser.createDialog(ColorChooserPanel.this, "Background Color",
60                false /* not modal */, chooser,
61                event -> setBackground(chooser.getColor()),
62                null /* no Cancel button listener */);
63       }
64
65       public void actionPerformed(ActionEvent event)
66       {
67          chooser.setColor(getBackground());
68          dialog.setVisible(true);
69       }
70    }
71
72    /**
73     * This listener pops up a modeless color chooser. The panel color is changed immediately when
74     * the user picks a new color.
75     */
76    private class ImmediateListener implements ActionListener
77    {
78       private JDialog dialog;
79       private JColorChooser chooser;
80
81       public ImmediateListener()
82       {
83          chooser = new JColorChooser();
84          chooser.getSelectionModel().addChangeListener(
85                event -> setBackground(chooser.getColor()));
86
87          dialog = new JDialog((Frame) null, false /* not modal */);
88          dialog.add(chooser);
89          dialog.pack();
90       }
91
92       public void actionPerformed(ActionEvent event)
93       {
94          chooser.setColor(getBackground());
95          dialog.setVisible(true);
96       }
97    }
98 }

 1 package colorChooser;2 3 import javax.swing.*;4 5 /**6  * A frame with a color chooser panel7  */8 public class ColorChooserFrame extends JFrame9 {
10    private static final int DEFAULT_WIDTH = 300;
11    private static final int DEFAULT_HEIGHT = 200;
12
13    public ColorChooserFrame()
14    {
15       setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
16
17       // add color chooser panel to frame
18
19       ColorChooserPanel panel = new ColorChooserPanel();
20       add(panel);
21    }
22 }

实验2：组内讨论反思本组负责程序，理解程序总体结构，梳理程序GUI设计中应用的相关组件，整理相关组件的API,对程序中组件应用的相关代码添加注释。

实验3：组间协同学习：在本班课程QQ群内，各位同学对实验1中存在的问题进行提问，提问时注明实验1中的测试程序编号，负责对应程序的小组需及时对群内提问进行回答。

实验总结：这次主要负责的测试程序13在这个实验中12-17是测试程序框架类的代码，12-18是显示了对话框类。在实验中要实现一个对话框，需要从JDialong派生一个类。

在对话框构造器中，调用超类JDialong的构造器；添加用户框的用户界面组件；添加事件处理器；设置对话框的大小.。

在例子中添加的是标签和按钮，并且为按钮设置了处理器，还设置了对话框的大小。

拥有这框架控制对话框的显示位置，如果将拥有者标识为null，那么对话框将由一个隐藏框架所拥有。

在这个实验本来弄得时候就只有空的一个框架，后来在进行重新的导入就有了现在的对话框，在这次代码中只建立一次对话框，无论何时用户点击About按钮，都可以重复使用。

转载于:https://www.cnblogs.com/qiongji/p/10053637.html

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