鼠标监听

鼠标监听

• 实现鼠标描点

public class Demo06 {
    public static void main(String[] args) {
        new MyFrame("画图");
    }
}
class MyFrame extends Frame{
    //需要画笔，需要监听鼠标的位置，需要集合存储点
    ArrayList points;
    public MyFrame(String name){
        super(name);
        setBounds(200,200,300,300);
        //存入点
        points = new ArrayList();
        setVisible(true);
        //鼠标监听器。相对于窗口
        this.addMouseListener(new MyMouseListener());
    }
    @Override
    public void paint(Graphics g) {
        //监听鼠标的事件
        Iterator iterator = points.iterator();
        while (iterator.hasNext()){
            Point point = (Point) iterator.next();
            g.setColor(Color.cyan);
            g.fillOval(point.x,point.y,10,10);
        }
    }
    //添加一个点到界面上
    public void addPaint(Point point){
        points.add(point);
    }

    //适配器模式
    private class MyMouseListener extends MouseAdapter{
        //鼠标 ：按下、弹起、按住不放
        @Override
        public void mousePressed(MouseEvent e) {
            MyFrame myframe = (MyFrame) e.getSource();
            //这里我们点击的时候，就会在界面产生一个点
            myframe.addPaint(new Point(e.getX(),e.getY()));
            //每次点击鼠标都需要重新画一遍
            myframe.repaint();//刷新
        }
    }
}