java鼠标点击切换颜色_用java代码实现“用鼠标点击一个圆，并同时拖动鼠标，圆会变大并且同时改变颜色，移开鼠标停止拖动后，圆又恢复成起始大小和颜色”...

importjava.awt.Color;importjava.awt.Graphics;importjava.awt.event.MouseEvent;importjava.awt.event.MouseListener;importjava.awt.event.MouseMotionListener;importjavax.swing.JFrame;importjavax.swing.JPanel;public class DrawWithPanel extendsJFrame{private static final long serialVersionUID=1L;

DrawWithPanel(){super("可拖动的圆");this.getContentPane().add(newPaintPanel());this.setDefaultCloseOperation(EXIT_ON_CLOSE);this.setBounds(50,50,750,700);this.setVisible(true);

}class PaintPanel extends JPanel implementsMouseListener,MouseMotionListener{private static final long serialVersionUID=1L;

Color color=new Color(0,0,0);int startX=130,startY=140,width=150,height=150;publicPaintPanel() {

addMouseListener(this);

addMouseMotionListener(this);

}protected voidpaintComponent(Graphics g) {

g.setColor(Color.white);

g.fillRect(0, 0, 750, 700);

g.setColor(color);

g.fillOval(startX, startY, width, height);

}

@Overridepublic voidmouseDragged(MouseEvent e) {

color=Color.pink;

startX=startX+2;

startY=startY+2;

width=width+2;

height=height+2;

repaint();

}

@Overridepublic voidmouseMoved(MouseEvent e) {

}

@Overridepublic voidmouseClicked(MouseEvent e) {

color=Color.yellow;

startX=130;

startY=140;

width=150;

height=150;

repaint();

}

@Overridepublic voidmousePressed(MouseEvent e) {

}

@Overridepublic voidmouseReleased(MouseEvent e) {

color=Color.blue;

startX=130;

startY=140;

width=150;

height=150;

repaint();

}

@Overridepublic voidmouseEntered(MouseEvent e) {

}

@Overridepublic voidmouseExited(MouseEvent e) {

}

}public static voidmain(String args[])

{newDrawWithPanel();

}

}