java事件处理3

鼠标拖动事件

接口MouseMotionListener

两个方法

mouseDragged(MouseEvent)//拖动鼠标
mouseMoved(MouseEvent)//移动鼠标

一个拖动按钮的例子

public class test{

    public static void main(String args[]){
        MyWin window1=new MyWin();
        window1.setBounds(12,12,300,300);
    }
}

class MyWin extends JFrame{
    MousePolice mouseListener1;
    MyWin(){
        init();
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
    void init(){
        mouseListener1=new MousePolice();
        add(mouseListener1,BorderLayout.CENTER);
    }
}

class MousePolice extends JLayeredPane implements MouseListener,MouseMotionListener{
    JButton button1;
    int x,y,a,b,x0,y0;
    MousePolice(){
        button1=new JButton("move me");
        button1.addMouseListener(this);
        button1.addMouseMotionListener(this);
        setLayout(new FlowLayout());
        add(button1,JLayeredPane.DEFAULT_LAYER);
    }
    public void mousePressed(MouseEvent e){
//        JComponent e1=(JComponent)e.getSource();
//        setLayer(e1,JLayeredPane.DRAG_LAYER);//不明白书上有何用意
//        a=e1.getBounds().x;
//        b=e1.getBounds().y;
        x0=e.getX();
        y0=e.getY();
        System.out.println("11");
    }
    public void mouseReleased(MouseEvent e){
//        JComponent e1=(JComponent)e.getSource();
//        setLayer(e1,JLayeredPane.DEFAULT_LAYER);
//        System.out.println("22");
    }
    public void mouseEntered(MouseEvent e){}
    public void mouseExited(MouseEvent e){}
    public void mouseClicked(MouseEvent e){}
    public void mouseMoved(MouseEvent e){}
    public void mouseDragged(MouseEvent e){
        Component com=null;
        if(e.getSource() instanceof JButton){
            com=(Component)e.getSource();
            a=com.getBounds().x;
            b=com.getBounds().y;
            x=e.getX();
            y=e.getY();
            com.setLocation(a+x-x0,b+y-y0);//公式：组件地址+现在鼠标地址-之前鼠标地址
            System.out.println("33");
        }
    }
}