Java 窗口焦点事件的意外行为

我正在使用

Swing

创建一个应用程序，我遇到了一个问题。我想处理

focusLost（）

和

focusgoven（）

事件，但我认为我的代码有缺陷

我有以下测试代码：

addWindowFocusListener(new WindowFocusListener() {
    @Override
    public void windowLostFocus(WindowEvent e) {
        System.out.println("Lost!");
        System.out.println(e.toString());
    }

    @Override
    public void windowGainedFocus(WindowEvent e) {
        System.out.println("Gained!");
        System.out.println(e.toString());
    }
});

而且，当我激活该窗口时，该应用程序似乎可以同时处理两个事件：

Gained! java.awt.event.WindowEvent[WINDOW_GAINED_FOCUS,opposite=null,oldState=0,newState=0] on frame0 Lost! java.awt.event.WindowEvent[WINDOW_LOST_FOCUS,opposite=null,oldState=0,newState=0] on frame0

---

嗯，我看不出你的代码有什么错；因此，我制作了一个快速演示，它似乎运行良好：

import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class WindowEventDemo extends JFrame implements WindowFocusListener {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new WindowEventDemo("Window Event Demo").setVisible(true);
            }
        });
    }

    public WindowEventDemo(String name) {
        super(name);
        addWindowFocusListener(this);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 300);
    }

    @Override
    public void windowGainedFocus(WindowEvent e) {
        System.out.println("WindowFocusListener method called: windowGainedFocus.");
    }

    @Override
    public void windowLostFocus(WindowEvent e) {
        System.out.println("WindowFocusListener method called: windowLostFocus.");
    }
}

启动时打印：

WindowFocusListener方法名为：windowGainedFocus

当窗口最小化时，或者在屏幕上的其他地方单击鼠标时会打印

JFrame

：

WindowFocusListener方法名为：windowLostFocus

---

你能发布一个演示你的问题（即可以按原样运行的东西）吗？请发布代码。由于我对问题的政策，我给了你一张赞成票，从而取消了反对票。现在我不能。。。我给自己写了一个简单的例子，但一切都没问题。一个应用程序，我有这个问题是一个有点大的应用程序，所以我不能上传那里的代码。我认为问题可能是由jMonkeyEngine（lwjgl）画布引起的。如果我能写SSCE，我会写它…是的，我删除了jME画布，它工作正常。我会尽可能快地编写一个示例代码。听起来你在混合AWT和Swing。

import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class WindowEventDemo extends JFrame implements WindowFocusListener {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new WindowEventDemo("Window Event Demo").setVisible(true);
            }
        });
    }

    public WindowEventDemo(String name) {
        super(name);
        addWindowFocusListener(this);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 300);
    }

    @Override
    public void windowGainedFocus(WindowEvent e) {
        System.out.println("WindowFocusListener method called: windowGainedFocus.");
    }

    @Override
    public void windowLostFocus(WindowEvent e) {
        System.out.println("WindowFocusListener method called: windowLostFocus.");
    }
}