该楼层疑似违规已被系统折叠 隐藏此楼查看此楼

先献上代码

import java.awt.Color;

import java.awt.Component;

import java.awt.Font;

import java.awt.Graphics;

import java.awt.Panel;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.util.ArrayList;

import java.util.List;

import javax.swing.JFrame;

import javax.swing.JPanel;

public class 能画画的画板 extends JFrame{

MyPanel mp = new MyPanel();

public 能画画的画板() {

this.add(mp);

mp.addMouseListener(new MyMouse());

mp.addMouseMotionListener(new MyMouse());

showMe();

}

class MyMouse extends MouseAdapter{

@Override

public void mousePressed(MouseEvent e) {

if (mp.mylist==null) {

mp.mylist = new ArrayList<>();

}

// System.out.println("压了一下。");

mp.mylist.add(new GetLocation(e.getX(), e.getY()));

mp.repaint();

}

@Override

public void mouseReleased(MouseEvent e) {

// System.out.println("松了一下。");

mp.mylist.add(new GetLocation(e.getX(), e.getY()));

mp.repaint();

}

@Override

public void mouseDragged(MouseEvent e) {

// System.out.println("拖了一下。");

mp.mylist.add(new GetLocation(e.getX(), e.getY()));

mp.setBackground(Color.red);

mp.repaint();

}

}

private void showMe() {

this.setBounds(100, 50, 500, 500);

this.setVisible(true);

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

public static void main(String[] args) {

new 能画画的画板();

System.out.println();

}

class MyPanel extends Panel{

List< GetLocation> mylist = null;

@Override

public void paint(Graphics g) {

if (mylist!=null) {

GetLocation g0 = mylist.get(0);

for (int i = 1; i < mylist.size(); i++) {

GetLocation g1 = mylist.get(i);

g.drawLine(g0.x, g0.y, g1.x, g1.y);

g0=g1;

}

}

}

}

class GetLocation{

private int x,y;

public GetLocation(int x, int y) {

this.x = x;

this.y = y;

}

public int getX() {

return x;

}

public int getY() {

return y;

}

@Override

public String toString() {

return "GetLocation [x=" + x + ", y=" + y + "]";

}

}

}

看在这么辛苦弄格式的份上帮帮忙呗，好吧 好像忘记说问题了。。

问题就是 运行这段代码的时候，发现画出的 第二条线 和 第一条线

自动首尾相连了，怎么解决这个问题？