Question

我想制作一个有这些目标的计划：

1）制作JButton 2）使用KeyBindings将按钮连接到一个键（“A”键） 3）单击“A”时执行一些代码

这是我到目前为止的代码：

// Imports

Public class Test{

JButton button = new JButton();

//...

Test(){

button.getInputMap().put(KeyStroke.getKeyStroke("A"), "Pressed");


//...

}

// Where do I add the code that responds when button is pressed?
}

现在，在按下按钮时，我在哪里添加我希望它执行的代码？

Answer 1

我能想到的两种方式：

让JButton和Key Bindings共享相同的AbstractAction，或者更好的
只需在键绑定按钮上调用doClick()即可。

KeyBindingEg.java

import java.awt.event.*;
import javax.swing.*;

public class KeyBindingEg extends JPanel {
   private JButton btnA = new JButton();

   public KeyBindingEg() {
      Action btnAction = new ActionOne("A");
      Action keyBindingAction = new ActionTwo();

      int condition = JLabel.WHEN_IN_FOCUSED_WINDOW;
      InputMap inputmap = btnA.getInputMap(condition);
      ActionMap actionmap = btnA.getActionMap();

      final String aKeyPressed = "a key pressed";
      inputmap.put(KeyStroke.getKeyStroke(KeyEvent.VK_A, 0), aKeyPressed );

      actionmap.put(aKeyPressed, keyBindingAction);
      // actionmap.put(aKeyPressed, btnAction); // one or the other, your choice

      btnA.setAction(btnAction);
      add(btnA);
   }

   private class ActionOne extends AbstractAction {
      public ActionOne(String text) {
         super(text);
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         sharedMethod();
      }
   }

   private class ActionTwo extends AbstractAction {
      @Override
      public void actionPerformed(ActionEvent e) {
         btnA.doClick();
      }
   }

   private void sharedMethod() {
      System.out.println("Method called by either key bindings or action listener");
   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("KeyBindingEg");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(new KeyBindingEg());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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

Answer 2

您需要添加一个动作侦听器，特别针对actionPerformed。在构造函数中的某处声明：

import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;

public class Main {
    public static void main(String[] argv) throws Exception {

        JButton component = new JButton();
        MyAction action = new MyAction();
        component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("F2"),
            action.getValue(Action.NAME));
    }
}

class MyAction extends AbstractAction {
    public MyAction() {
        super("my action");
    }

    public void actionPerformed(ActionEvent e) {
        //Here goes the code where the button does something
        System.out.println("hi");//In this case we print hi
    }
}

在这个例子中，如果我们按F2，它将相当于按下按钮。

使用KeyBIndings响应Button

2 个答案: