试图移动不受欢迎的Jframe时抖动

Question

我制作了一个未经装修的mainWindow JFrame。我在其顶部添加了一个名为dragBar的JLabel，并给了它所需的尺寸(如下所示(。当我单击标签时，我会使用两个侦听器根据鼠标将窗口移动；一个MouseListener和一个MouseMotionListener。
问题是，每当我单击标签时，窗口的确会根据鼠标的位置移动，但是它会在屏幕上散布到整个屏幕上，直到我停止移动鼠标或单击按钮。
我的方法错了吗？是什么原因导致了这个问题？这是我的代码：

    //what i use to make the dragBar
    private JLabel dragBar = new JLabel();
    private Point initialClick; //the initial point where I click on the label
    //my mainWindow JFrame
    private JFrame mainWindow = new JFrame();
    private Dimension mainWindowSize = new Dimension(680,410);
    //the code I use to set up my mainWindow JFrame
    mainWindow.setUndecorated(true);
    mainWindow.setShape(new RoundRectangle2D.Double(0, 0, 670, 400, 5, 5));
    mainWindow.setSize(mainWindowSize);
    mainWindow.setMinimumSize(mainWindowSize);
    mainWindow.setResizable(false);
    mainWindow.setLocation((screen_size.width/2)- mainWindow.getWidth()/2, (screen_size.height/2)- mainWindow.getHeight()/2);
    mainWindow.getContentPane().setBackground(new Color(46, 48, 50, 255));
    //the code I use to set up my dragBar label
    topContainer.add(dragBar,3); //a Jlayeredpane that contains the dragBar label and is added to the mainWindow
    dragBar.setSize(topContainer.getSize());
    dragBar.setLocation(0,0);
    dragBar.addMouseListener(new MouseListener() {
        @Override public void mouseClicked(MouseEvent e) {}
        @Override
        public void mousePressed(MouseEvent e) {
            initialClick = e.getPoint();
        }
        @Override public void mouseReleased(MouseEvent e) {}
        @Override public void mouseEntered(MouseEvent e) {}
        @Override public void mouseExited(MouseEvent e) {}
    });
    dragBar.addMouseMotionListener(new MouseMotionListener() {
        @Override
        public void mouseDragged(MouseEvent e) {
            int changeX = e.getX()-initialClick.x;
            int changeY = e.getY()-initialClick.y;
            mainWindow.setLocation(mainWindow.getX()+changeX, mainWindow.getY()+changeY);
        }
        @Override public void mouseMoved(MouseEvent e) {}
    });

Answer 1

包含dragbar标签的jlayeredpane

不要以为我会使用jlayeredpane。只需在框架的BorderLayout.PAGE_START中添加一个组件即可。

拖动组件的基本逻辑是：

public class DragListener extends MouseInputAdapter
{
    Point location;
    MouseEvent pressed;
    public void mousePressed(MouseEvent me)
    {
        pressed = me;
    }
    public void mouseDragged(MouseEvent me)
    {
        Component component = me.getComponent();
        location = component.getLocation(location);
        int x = location.x - pressed.getX() + me.getX();
        int y = location.y - pressed.getY() + me.getY();
        component.setLocation(x, y);
     }
}

但是，在您的情况下，您不想拖动标签，而是拖动窗口，您的逻辑需要将事件转发到窗口。

查看移动窗口以进行上述代码的更复杂的实现，该代码还添加了其他功能，可以轻松地移动窗口。