java - 移动框架的鼠标事件不起作用

Question

我有以下代码:

panel.addMouseListener(new MouseAdapter() {
    public void mouseDragged(MouseEvent e) {
        frame.setLocation(e.getXOnScreen(), e.getYOnScreen());
    }
});

panel 是一个JPanel，并且所有导入都已包含在内。现在，当我拖动面板时，框架不会移动一点点。这是为什么？我应该如何解决它？

编辑:框架未装饰。
编辑:mouseDragged没有被触发 - 这就是需要解决的问题! 编辑:代码!!!!!!

package user_interface;

import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Test extends JFrame {
    public Test() {
        this.setUndecorated(true);
        this.setLayout(new GridLayout(3, 3, 3, 3));
        for (int i = 0; i < 4; i++) {
            this.add(new JPanel());
        }
        JPanel panel = new JPanel();
        panel.setBackground(new Color(0));
        panel.setToolTipText("Drag to move frame");
        this.addMouseListener(new MouseAdapter() {
            public void mouseDragged(MouseEvent e) {
                Test.this.setLocation(e.getXOnScreen(), e.getYOnScreen());
                System.out.println(e);
            }
        });
        this.add(panel);
        for (int i = 0; i < 4; i++) {
            this.add(new JPanel());
        }
    }

    public static void main(String... args) {
        Test test = new Test();
        test.setSize(750, 500);
        test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // 3
        test.setVisible(true);
    }
}

Answer 1

为此目的添加 MouseMotionListener。

JPanel panel = new JPanel();
panel.setBackground(new Color(0));
panel.setToolTipText("Drag to move frame");

panel.addMouseMotionListener(new MouseMotionAdapter() {
    public void mouseDragged(MouseEvent e) {
       super.mouseDragged(e);
       Test.this.setLocation(e.getXOnScreen(), e.getYOnScreen());
       System.out.println(e);
    }
});

this.setContentPane(panel);