java中解决组件重叠的问题（例如鼠标移动组件时）

小灰灰 2022-01-26 12:15 307阅读 0赞

java中解决组件覆盖的问题！  
有时候在移动组件的时候会出现两个组件覆盖的情况，但是你想让被覆盖的组件显示出来或者不被覆盖！  
在设计GUI时已经可以定义组件的叠放次序了（按摆放组件的先后顺序）。  
真正麻烦的是响应哪个组件，这就要创建一个链表，把组件对象按顺序存起来，响应事件时扫描这个链表，按  
链表中的先后顺序选择响应组件对象。  
所以要想满足自己的需求，那么在添加组件的时候就要注意顺序就好了！

另外如果不想用上面的方法，那么你就采用JLayeredPane这个类，分层面板可以帮助你解决覆盖中的问题！

*例如moveToFront(Componet), moveToBack(Component), setPosition(), setLayer()。。。。*

import java.awt.Button;
    import java.awt.Dimension;
    import java.awt.FlowLayout;
    import java.awt.Frame;
    import java.awt.Point;
    import java.awt.event.MouseAdapter;
    import java.awt.event.MouseEvent;
    import java.awt.event.MouseMotionAdapter;
    import java.awt.event.WindowAdapter;
    import java.awt.event.WindowEvent;
     
    import javax.swing.JLayeredPane;
     
    //实现鼠标移动组件的小程序
    public class ParentAndChild {
     
        static Point oldPt;
        static JLayeredPane pane = new JLayeredPane();
        static Button btn = new Button(), btn1 = new Button("嘻嘻嘻");
        public static void main(String[] args) {
            Frame fm = new Frame("哈哈哈");
            fm.setVisible(true);
            pane.setLayout(new FlowLayout());
            fm.add(pane, "Center");
            btn.setLabel("啦啦啦");
            btn.addMouseListener(new MouseAdapter() {
                    public void mousePressed(MouseEvent e) {
                        oldPt=e.getLocationOnScreen();
                    }
                    public void mouseReleased(MouseEvent e) {
                         pane.setPosition(btn, -1);
                    } 
            });
             
            btn.addMouseMotionListener(new MouseMotionAdapter() {
                    public void mouseDragged(MouseEvent e) {
                         Point pt = e.getLocationOnScreen();
                         btn.setLocation(new Point(btn.getX() + pt.x-oldPt.x,
                                         btn.getY() + pt.y-oldPt.y));
                         oldPt=pt;
                    }
                     
            });
                 
             
            btn.setPreferredSize(new Dimension(200, 100));
            pane.add(btn);
            pane.add(btn1);
            fm.setSize(new Dimension(600, 800));
             
             
            fm.addWindowListener(new WindowAdapter() {
                    public void windowClosing(WindowEvent e) {
                        System.exit(0);
                    }
            });
        }
     
    }