让JFrame关闭的正确方法是什么,就像用户按下X关闭按钮,或按下Alt+F4(在Windows上)一样?

我的默认关闭操作设置为我想要的方式,通过:

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

它完全符合我对上述控件的要求。这个问题与此无关。

我真正想做的是使GUI的行为与按下X关闭按钮所引起的行为相同。

假设我要扩展WindowAdaptor,然后通过addWindowListener()将适配器的一个实例添加为侦听器。我希望看到通过windowDeactivated()、windowClosing()和windowClosed()的调用序列与X close按钮相同。可以说,与其说是撕破窗户,不如说是让它自己撕毁。


当前回答

本示例演示了如何实现确认窗口关闭操作。

窗口有一个窗口适配器,它将默认关闭操作切换为exit_on_close或DO_NOTHING_ON_CLOSE,这取决于您在OptionDialog中的答案。

ConfirmedCloseWindow的closeWindow方法触发关闭窗口事件,可以在任何地方使用,即作为菜单项的动作

public class WindowConfirmedCloseAdapter extends WindowAdapter {

    public void windowClosing(WindowEvent e) {

        Object options[] = {"Yes", "No"};

        int close = JOptionPane.showOptionDialog(e.getComponent(),
                "Really want to close this application?\n", "Attention",
                JOptionPane.YES_NO_OPTION,
                JOptionPane.INFORMATION_MESSAGE,
                null,
                options,
                null);

        if(close == JOptionPane.YES_OPTION) {
           ((JFrame)e.getSource()).setDefaultCloseOperation(
                   JFrame.EXIT_ON_CLOSE);
        } else {
           ((JFrame)e.getSource()).setDefaultCloseOperation(
                   JFrame.DO_NOTHING_ON_CLOSE);
        }
    }
}

public class ConfirmedCloseWindow extends JFrame {

    public ConfirmedCloseWindow() {

        addWindowListener(new WindowConfirmedCloseAdapter());
    }

    private void closeWindow() {
        processWindowEvent(new WindowEvent(this, WindowEvent.WINDOW_CLOSING));
    }
}

其他回答

本示例演示了如何实现确认窗口关闭操作。

窗口有一个窗口适配器,它将默认关闭操作切换为exit_on_close或DO_NOTHING_ON_CLOSE,这取决于您在OptionDialog中的答案。

ConfirmedCloseWindow的closeWindow方法触发关闭窗口事件,可以在任何地方使用,即作为菜单项的动作

public class WindowConfirmedCloseAdapter extends WindowAdapter {

    public void windowClosing(WindowEvent e) {

        Object options[] = {"Yes", "No"};

        int close = JOptionPane.showOptionDialog(e.getComponent(),
                "Really want to close this application?\n", "Attention",
                JOptionPane.YES_NO_OPTION,
                JOptionPane.INFORMATION_MESSAGE,
                null,
                options,
                null);

        if(close == JOptionPane.YES_OPTION) {
           ((JFrame)e.getSource()).setDefaultCloseOperation(
                   JFrame.EXIT_ON_CLOSE);
        } else {
           ((JFrame)e.getSource()).setDefaultCloseOperation(
                   JFrame.DO_NOTHING_ON_CLOSE);
        }
    }
}

public class ConfirmedCloseWindow extends JFrame {

    public ConfirmedCloseWindow() {

        addWindowListener(new WindowConfirmedCloseAdapter());
    }

    private void closeWindow() {
        processWindowEvent(new WindowEvent(this, WindowEvent.WINDOW_CLOSING));
    }
}

如果你这样做是为了确保用户不能关闭窗口:

frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);

然后您应该将pullThePlug()方法更改为

public void pullThePlug() {
    // this will make sure WindowListener.windowClosing() et al. will be called.
    WindowEvent wev = new WindowEvent(this, WindowEvent.WINDOW_CLOSING);
    Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(wev);

    // this will hide and dispose the frame, so that the application quits by
    // itself if there is nothing else around. 
    setVisible(false);
    dispose();
    // if you have other similar frames around, you should dispose them, too.

    // finally, call this to really exit. 
    // i/o libraries such as WiiRemoteJ need this. 
    // also, this is what swing does for JFrame.EXIT_ON_CLOSE
    System.exit(0); 
}

我发现这是唯一的方法,发挥良好的WindowListener和JFrame.DO_NOTHING_ON_CLOSE。

以编程方式关闭Swing帧的最佳方法是使它的行为与按下“X”按钮时一样。要做到这一点,你需要实现适合你的需要的WindowAdapter,并设置帧的默认关闭操作为什么都不做(DO_NOTHING_ON_CLOSE)。

像这样初始化你的框架:

private WindowAdapter windowAdapter = null;

private void initFrame() {

    this.windowAdapter = new WindowAdapter() {
        // WINDOW_CLOSING event handler
        @Override
        public void windowClosing(WindowEvent e) {
            super.windowClosing(e);
            // You can still stop closing if you want to
            int res = JOptionPane.showConfirmDialog(ClosableFrame.this, "Are you sure you want to close?", "Close?", JOptionPane.YES_NO_OPTION);
            if ( res == 0 ) {
                // dispose method issues the WINDOW_CLOSED event
                ClosableFrame.this.dispose();
            }
        }

        // WINDOW_CLOSED event handler
        @Override
        public void windowClosed(WindowEvent e) {
            super.windowClosed(e);
            // Close application if you want to with System.exit(0)
            // but don't forget to dispose of all resources 
            // like child frames, threads, ...
            // System.exit(0);
        }
    };

    // when you press "X" the WINDOW_CLOSING event is called but that is it
    // nothing else happens
    this.setDefaultCloseOperation(ClosableFrame.DO_NOTHING_ON_CLOSE);
    // don't forget this
    this.addWindowListener(this.windowAdapter);
}

你可以通过发送WINDOW_CLOSING事件来关闭帧,就像这样:

WindowEvent closingEvent = new WindowEvent(targetFrame, WindowEvent.WINDOW_CLOSING);
Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(closingEvent);

这将关闭框架,就像“X”按钮被按下。

您必须将调用插入到AWT消息队列中,以便所有计时都正确发生,否则它将无法分派正确的事件序列,特别是在多线程程序中。当这一步完成后,你可以处理结果事件序列,就像用户点击操作系统提供的装饰JFrame的[x]按钮一样。

public void closeWindow()
{
    if(awtWindow_ != null) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                awtWindow_.dispatchEvent(new WindowEvent(awtWindow_, WindowEvent.WINDOW_CLOSING));
            }
        });
    }
}

如果您不希望您的应用程序在JFrame关闭时终止, 使用: setDefaultCloseOperation (JFrame.DISPOSE_ON_CLOSE)

而不是: setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

从文档中可以看到:

DO_NOTHING_ON_CLOSE(在WindowConstants中定义):不做任何事情;要求程序处理注册的WindowListener对象的windowClosing方法中的操作。

HIDE_ON_CLOSE(在WindowConstants中定义):在调用任何注册的WindowListener对象后自动隐藏帧。

DISPOSE_ON_CLOSE(在WindowConstants中定义):在调用任何注册的WindowListener对象后自动隐藏和释放帧。

EXIT_ON_CLOSE(在JFrame中定义):使用系统退出方法退出应用程序。仅在应用程序中使用此选项。

可能仍然有用: 如果你想再次显示相同的帧,你可以在JFrame上使用setVisible(false)。 否则调用dispose()删除所有本机屏幕资源。

抄自彼得·朗

https://stackoverflow.com/a/1944474/3782247