FocusListener行为

Question

我有一个JFrame，当用户单击它时，我希望将其关闭。我有两个JTextFields和一个提交(用户名、密码、JButton )。当我给他们所有的FocusListener时，只要用户从一个字段转到另一个字段，窗口就会关闭。如何才能允许用户从一个字段转到另一个字段，并仅在用户单击弹出窗口之外的任何位置时才将其关闭？

public class LoginForm {

    static JTextField userName;
    static JTextField password;
    static JButton submit;
    JFrame main;
    Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();

    UserSession session;

    public LoginForm(){

        Handler handle = new Handler();  //inner class
        LoginFormFocusListener fl = new LoginFormFocusListener();   //inner class

        main = new JFrame("Please Login");

        main.setUndecorated(true);
        main.setBounds((dim.width/2) - (500/2),(dim.height/2) - (150/2),500,150);
        main.setVisible(true);
        main.setAlwaysOnTop(true);
        main.setResizable(false);
        main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        userName = new JTextField(10);
        password = new JTextField(10);
        main.setLayout(new GridLayout(0,1));

        JPanel panel = new JPanel();
        main.add(panel);
        panel.add(new JLabel("Username: "));
        panel.add(userName);
        panel.add(new JLabel("Password: "));
        panel.add(password);

        submit = new JButton("Submit");
        panel.add(submit);

        userName.addFocusListener(fl);
        password.addFocusListener(fl);
        submit.addFocusListener(fl);

        submit.addActionListener(handle);
    }
}

..。(忽略不重要的方法和"Handler“类)

public class LoginFormFocusListener implements FocusListener{

    public void focusGained(FocusEvent fe) {
        System.out.println("focus gained...");
        System.out.println("click off of this window to close...");
    }

    public void focusLost(FocusEvent fe){
    System.out.println("focus lost...");
    WindowEvent winEvt = new WindowEvent(main, 0);
    winEvt.getWindow().dispose();
    }

}



//test
public static void main(String args[]){
    SwingUtilities.invokeLater(new Runnable(){  
        public void run(){  
        new LoginForm();  
    }  
    });  
}

Answer 1

不要为此使用FocusListener，因为它们是用于获得和失去焦点的组件，而不是用于顶级窗口。也许使用WindowListener监听窗口是停用的或图标化的。

例如：

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class WindowListenerFun {
   public static void main(String[] args) {
      JPanel panel = new JPanel();
      panel.add(new JTextField(10));
      panel.add(new JButton("button"));
      JFrame frame = new JFrame("Bad Frame");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.add(panel);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);

      frame.addWindowListener(new WindowAdapter() {

         @Override
         public void windowIconified(WindowEvent wEvt) {
            ((JFrame)wEvt.getSource()).dispose();
         }

         @Override
         public void windowDeactivated(WindowEvent wEvt) {
            ((JFrame)wEvt.getSource()).dispose();
         }

      });
   }
}