import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class TestMouseLine extends JFrame
{
int x,y;
int endX,endY;
public TestMouseLine()
{
Container c=getContentPane();

addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
x=e.getX();
y=e.getY();
}
});

addMouseMotionListener(new MouseMotionAdapter()
{
public void mouseDragged(MouseEvent e)
{
endX = e.getX();
endY = e.getY();
repaint();
}
});

addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});

setSize(400,300);
setLocation(400,300);
show();
}
public void paint(Graphics g)
{
g.setColor(Color.red);
g.drawLine(x,y,endX,endY);
}

public static void main(String[] args)
{
new TestMouseLine();
}
}
为什么用鼠标画的时候有很多线呢?怎么样才能只有一跟线随着鼠标转呢?

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class TestMouseLine extends JFrame
{
int x,y;
int endX,endY;
ArrayList list;
public TestMouseLine()
{
Container c=getContentPane();
list=new ArrayList();

addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
x=e.getX();
y=e.getY();
}
});

addMouseMotionListener(new MouseMotionAdapter()
{
public void mouseDragged(MouseEvent e)
{
endX = e.getX();
endY = e.getY();
repaint();
}
});

addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});

setSize(400,300);
setLocation(400,300);
show();
}
public void paint(Graphics g)
{
super.paint(g);
list.add(new MyLine(x,y,endX,endY));
Iterator it=list.iterator();
while(it.hasNext())
{
MyLine line=(MyLine)it.next();
line.drawMe(g);
}
}

public static void main(String[] args)
{
new TestMouseLine();
}
}
class MyLine
{
private int x,y;
private int endX,endY;
public MyLine(int x,int y,int endX,int endY)
{
this.x = x;
this.y = y;
this.endX = endX;
this.endY = endY;
}
public void drawMe(Graphics g)
{
g.setColor(Color.RED);
g.drawLine(x,y,endX,endY);
}
};
我重新改了之后的代码,为什么还是有那个问题啊?就是有很多线跟着鼠标转.......