我测试了下，把你的panel1.setAlignmentX(JPanel.LEFT_ALIGNMENT);改为

panel1.setLayout(new FlowLayout(FlowLayout.LEFT));这样应该行了。

下面是我的测试代码：

import java.awt.FlowLayout;

import java.awt.GridLayout;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

public class TestJPanel {

public TestJPanel() {

JFrame frame = new JFrame();

frame.setLayout(new GridLayout(3,0));

//设置JPanel的对齐方式，暂时发现只有这样才能使JPanel改变对齐方式。

JPanel JP1 = new JPanel();

JP1.setLayout(new FlowLayout(FlowLayout.LEFT));

JPanel JP2 = new JPanel();

JP2.setLayout(new FlowLayout(FlowLayout.LEFT));

JPanel JP3 = new JPanel();

JP3.setLayout(new FlowLayout(FlowLayout.LEFT));

//测试标签

JLabel JL1 = new JLabel("测试1");

JLabel JL2 = new JLabel("测试2");

JLabel JL3 = new JLabel("测试三");

//增加则是标签

JP1.add(JL1);

JP2.add(JL2);

JP3.add(JL3);

//增加JPanel

frame.add(JP1);

frame.add(JP2);

frame.add(JP3);

frame.setVisible(true);

frame.setSize(300, 300);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args) {

new TestJPanel();

}

}

附上运行图片

追问：

你说的那一句我已经打上了啊～～～改了就变成写了两次了···

回答：

add(panel1,BorderLayout.NORTH);

add(panel2,BorderLayout.NORTH);

add(panel3,BorderLayout.NORTH);

add(push);

上面这一部分有问题，你的代码我整理下如下：

import java.awt.BorderLayout;

import java.awt.FlowLayout;

import java.awt.GridLayout;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JPanel;

import javax.swing.JTextField;

public class TestJPanel {

JLabel Label1;

JLabel Label2;

JLabel Label3;

JPanel panel1;

JPanel panel2;

JPanel panel3;

JPanel panel4;

JTextField TextField1;

JTextField TextField2;

JTextField TextField3;

JButton push;

public TestJPanel() {

JFrame frame = new JFrame();

frame.setLayout(new GridLayout(4,0)); //用GridLayout布局实现

Label1 = new JLabel("To");

Label1.setAlignmentX(JLabel.LEFT_ALIGNMENT);

Label2 = new JLabel("CC");

Label3 = new JLabel("Bcc");

panel1 = new JPanel();

panel2 = new JPanel();

panel3 = new JPanel();

panel4 = new JPanel();

panel1.setLayout(new FlowLayout(FlowLayout.LEFT));

panel2.setLayout(new FlowLayout(FlowLayout.LEFT));

panel3.setLayout(new FlowLayout(FlowLayout.LEFT));

TextField1 = new JTextField(30);

TextField2 = new JTextField(30);

TextField3 = new JTextField(45);

push = new JButton("Send");

panel4.add(push);

// push.addActionListener(new ButtonListener());

panel1.add(Label1);

panel1.add(TextField1);

panel2.add(Label2);

panel2.add(TextField2);

panel3.add(Label3);

panel3.add(TextField3);

frame.add(panel1);

frame.add(panel2);

frame.add(panel3);

frame.add(panel4);

frame.setVisible(true);

frame.setSize(300, 300);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args) {

new TestJPanel();

}

}

效果图如下