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。
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。
将问题正文中的内容作为CW答案。
想分享的成果,主要来源于关注camickr的链接。基本上我需要抛出一个WindowEvent。应用程序事件队列上的WINDOW_CLOSING。下面是解决方案的概要
// closing down the window makes sense as a method, so here are
// the salient parts of what happens with the JFrame extending class ..
public class FooWindow extends JFrame {
public FooWindow() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(5, 5, 400, 300); // yeah yeah, this is an example ;P
setVisible(true);
}
public void pullThePlug() {
WindowEvent wev = new WindowEvent(this, WindowEvent.WINDOW_CLOSING);
Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(wev);
}
}
// Here's how that would be employed from elsewhere -
// someplace the window gets created ..
FooWindow fooey = new FooWindow();
...
// and someplace else, you can close it thusly
fooey.pullThePlug();