vic*_*icd 7 java user-interface swing
我有一个问题,为什么在我的测试代码中没有调用"windowClosed"方法如下,
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
public class Tmp {
class TFrame extends JFrame{
private static final long serialVersionUID = -5729542298504858399L;
public TFrame() {
setTitle("title");
setSize(300, 300);
}
}
public static void main(String[] args) {
final TFrame t = new Tmp().new TFrame();
t.addWindowStateListener(new WindowAdapter() {
@Override
public void windowStateChanged(WindowEvent e) {
super.windowStateChanged(e);
System.out.println(e.getOldState() + "<-old new->" + e.getNewState());
}
});
t.addWindowListener(new WindowAdapter() {
@Override
public void windowClosed(WindowEvent e) {
super.windowClosed(e);
System.out.println(e.getID() + "closed " + e.getNewState());
}
@Override
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.out.println(e.getID() + "closing" + e.getNewState());
}
});
t.setVisible(true);
}
}
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如果我写语句setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE)或显式调用dispose()到TFrame,windowClosed()将被调用.
是否有人可以更详细地解释它,我很困惑为windowClosed()编写监听器的属性方式,提前感谢.
//////////////////根据Dan //////////////的一些导游更新
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class Tmp {
class TFrame extends JFrame {
// ignored .....
t.addWindowListener(new WindowAdapter() {
@Override
public void windowClosed(WindowEvent e) {
super.windowClosed(e);
System.out.println(e.getID() + "closed " + e.getNewState());
}
@Override
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.out.println(e.getID() + "closing" + e.getNewState());
int quit = JOptionPane.showConfirmDialog(t, "Are you sure to quit?");
if(quit == JOptionPane.YES_OPTION){
t.dispose();
}
else if (quit == JOptionPane.NO_OPTION){
t.setVisible(false);
}
}
});
t.setVisible(true);
t.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
}
}
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setDefaultCloseOperationis 的默认值HIDE_ON_CLOSE.有了这个,窗口没有关闭,它只是隐藏.
将值更改为其他值,您可以将其实际关闭而不是仅隐藏它,因此将触发事件.