java - setDefaultCloseOperation 不适用于 JButton

Question

我创建了三个类:

public class Gui extends JFrame {

private final JButton buttonClose = new JButton("Close");

private final MyButtonListener buttonListener = new MyButtonListener(this);
private final MyWindowListener windowListener = new MyWindowListener();

public SwitchGuiExtListeners() {
    super("Switch");
    setSize(200, 150);
    setLayout(new BorderLayout());
    add(buttonClose, BorderLayout.EAST);
    buttonClose.addActionListener(this.buttonListener);
    this.addWindowListener(this.windowListener);
    setVisible(true);
}

public JButton getButtonClose() {
    return buttonClose;
}
}

public class SwitchGuiWindowListener implements WindowListener{
...
@Override
    public void windowClosing(WindowEvent e) {
        System.exit(0);

    }
...
}

public class MyButtonListener implements ActionListener {
private final Gui gui;
public MyButtonListener (final Gui gui) {
    this.gui = gui;
}

@Override
public void actionPerformed(ActionEvent e) {
    if(e.getSource() == gui.getButtonClose()){
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //System.exit(0);
    }
}
}

如果我使用 gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);我的框架没有关闭。但是当我使用 System.exit(0) 时它就起作用了。为什么我不能使用 setDefaultCloseOperation(..)？

Answer 1

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 不会关闭 JFrame。它只是告诉 JFrame 必须在单击窗口右上角的关闭按钮时退出，即仅设置行为但会触发退出。

要关闭 JFrame，请使用如下内容:

frame.dispatchEvent(new WindowEvent(frame, WindowEvent.WINDOW_CLOSING));

来源:https://stackoverflow.com/a/1235994/1866196