Question

我的目标是简化此代码（一切正常）：

package test;

import java.awt.Window;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.JWindow;

public class A extends JWindow implements MouseListener, MouseMotionListener {

    public A() {
        addMouseListener(A.this);
        addMouseMotionListener(A.this);
    }

    @Override
    public void mouseClicked(MouseEvent e) {
    }

    @Override
    public void mousePressed(MouseEvent e) {
        //This method is being used, working fine
    }

    @Override
    public void mouseReleased(MouseEvent e) {
    }

    @Override
    public void mouseEntered(MouseEvent e) {
    }

    @Override
    public void mouseExited(MouseEvent e) {
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        //This method is being used, working fine
    }

    @Override
    public void mouseMoved(MouseEvent e) {
    }
}

但如果我决定像这样使用MouseAdapter：

addMouseListener(new MouseAdapter() {
    @Override
    public void mousePressed(MouseEvent e) {
        transferFocusBackward();
        //This method is being used, working fine
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        //This method is being used, not working anymore
    }
});

mouseDragged没有收到任何活动。但是如果我像这样添加MouseMotionListener：

addMouseListener(new MouseAdapter() {
    @Override
    public void mousePressed(MouseEvent e) {
        //This method is being used, working fine
    }
});

addMouseMotionListener(new MouseMotionAdapter() {
    @Override
    public void mouseDragged(MouseEvent e) {
        //This method is being used, working fine
    }
});

然后一切都恢复正常。所以我的问题是 - mouseDragged课程中mouseMoved，mouseWheelMoved和MouseAdapter方法的目的是什么？如果它们不起作用？

Answer 1

好吧，我想我现在明白了：在MouseAdapter类文档中，我们说“使用扩展类创建一个侦听器对象，然后使用组件的addMouseListener {{{{ 1}}，addMouseMotionListener方法“。现在它看起来像：

addMouseWheelListener

然后：

private class MouseListeners extends MouseAdapter {

    @Override
    public void mousePressed(MouseEvent e) {
        //This method is being used, working fine
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        //This method is being used, working fine
    }
}

现在一切都好。

MouseAdapter方法 - 为什么包括`mouseDragged`，`mouseMoved`和`mouseWheelMoved`？

1 个答案: