遍歷一組複選框

Question

如何使用Swing中的鍵盤箭頭鍵遍歷一組複選框？

注：複選框被放置在GridLayout

Answer 1

下面是基於How to Use the Focus Subsystem教程，註冊爲向前右邊和後邊的箭頭和向後焦點遍歷鍵的例子。

import java.awt.AWTKeyStroke; 
import java.awt.GridLayout; 
import java.awt.KeyboardFocusManager; 
import java.awt.event.KeyEvent; 
import java.util.HashSet; 
import java.util.Set; 
import javax.swing.JCheckBox; 
import javax.swing.JFrame; 
import javax.swing.KeyStroke; 
import javax.swing.SwingUtilities; 

public class CheckBoxDemo { 

    private static void createAndShowGUI() { 
     JFrame frame = new JFrame("Demo"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     frame.setLayout(new GridLayout(2, 2, 10, 10)); 

     frame.add(new JCheckBox("Bird")); 
     frame.add(new JCheckBox("Cat")); 
     frame.add(new JCheckBox("Dog")); 
     frame.add(new JCheckBox("Rabbit")); 

     Set<AWTKeyStroke> forwardKeys = frame.getFocusTraversalKeys(
       KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS); 
     Set<AWTKeyStroke> newForwardKeys = new HashSet<AWTKeyStroke>(forwardKeys); 
     newForwardKeys.add(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0)); 
     frame.setFocusTraversalKeys(
       KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, newForwardKeys); 

     Set<AWTKeyStroke> backwardKeys = frame.getFocusTraversalKeys(
       KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS); 
     Set<AWTKeyStroke> newBackKeys = new HashSet<AWTKeyStroke>(backwardKeys); 
     newBackKeys.add(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0)); 
     frame.setFocusTraversalKeys(
       KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, newBackKeys); 

     frame.pack(); 
     frame.setVisible(true); 

    } 

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