swing子界面关闭 父界面如何捕获？

Question

如题 
子界面closed事件出发后 父界面如何知道？

Answer 1

子界面如果是用 JDialog有两种情况，第一种如果dialog是模态： 
dialog.setModal(true);
dialog.setVisible(true);
// ...
当运行到 dialog.setVisible(true); 的时候，当前线程会被挂起，直到dialog被关闭之后才会返回，继续执行下面的代码。另外所有的 Window 的子类都可以 addWindowListener()，而WindowListener中有一个方法是void windowClosed(WindowEvent e) 通过这个就可以知道dialog关闭

Answer 2

addWindowListener()是在子页面中可以监听到JDialog是否可以关闭 
但是我子页面关闭后 想让父页面直接捕获到  可以么？
除了数据库和文件操作之外   父页面(panel)可以捕获到子页面(JDialog)是否关闭？

Answer 3

addWindowListener()WindowListener 可以写在任何地方，任何一个类只要 implements WindowListener 就可以加进去，你要在子对话框关闭的时候在父窗体运行任何逻辑，只要在父窗体的类中定义一个内部类，implements WindowListener，然后把它加进子对话框就行了：
  
  dialog.addWindowListener(new WindowAdapter() {
    
    @Override
    public void windowClosed(WindowEvent e) {
    
      // 这里调用你想要运行的逻辑
    }
  });

Answer 4

再请教一个问题 
为什么我子窗口每次关闭 
public void windowClosed(WindowEvent e) {} 都会执行3次？
有什么办法能让它只执行一次？

Answer 5

试试  void windowClosing(WindowEvent e)
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JDialog;
import javax.swing.SwingUtilities;
/**
 *
 * @date   13/11/2012
 */
public class TestWindowListener implements WindowListener{
  
  public static void main(String[] args) {
    
    SwingUtilities.invokeLater(new Runnable() {      @Override
      public void run() {
        
        JDialog d = new JDialog();
        d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        d.setSize(800, 500);
        d.setLocationRelativeTo(null);
        d.addWindowListener(new TestWindowListener());
        d.setVisible(true);
      }
    });
  }  @Override
  public void windowOpened(WindowEvent e) {
    
    System.out.println("windowOpened " + e);
  }  @Override
  public void windowClosing(WindowEvent e) {
    
    System.out.println("windowClosing " + e);
  }  @Override
  public void windowClosed(WindowEvent e) {
    
    System.out.println("windowClosed " + e);
  }  @Override
  public void windowIconified(WindowEvent e) {
    
    System.out.println("windowIconified " + e);
  }  @Override
  public void windowDeiconified(WindowEvent e) {
    
    System.out.println("windowDeiconified " + e);
  }  @Override
  public void windowActivated(WindowEvent e) {
    
    System.out.println("windowActivated " + e);
  }  @Override
  public void windowDeactivated(WindowEvent e) {
    
    System.out.println("windowDeactivated " + e);
  }
}---run:
windowActivated java.awt.event.WindowEvent[WINDOW_ACTIVATED,opposite=null,oldState=0,newState=0] on dialog0
windowOpened java.awt.event.WindowEvent[WINDOW_OPENED,opposite=null,oldState=0,newState=0] on dialog0
windowClosing java.awt.event.WindowEvent[WINDOW_CLOSING,opposite=null,oldState=0,newState=0] on dialog0
windowDeactivated java.awt.event.WindowEvent[WINDOW_DEACTIVATED,opposite=null,oldState=0,newState=0] on dialog0
windowClosed java.awt.event.WindowEvent[WINDOW_CLOSED,opposite=null,oldState=0,newState=0] on dialog0
windowClosed java.awt.event.WindowEvent[WINDOW_CLOSED,opposite=null,oldState=0,newState=0] on dialog0
BUILD SUCCESSFUL (total time: 3 seconds)