java - 如何确定通过Input/ActionMap绑定(bind)导致AbstractAction被触发的Key？

Question

我正在构建一个InputMap 和ActionMap 将键绑定(bind)到方法。许多按键都会执行类似的操作。我在输入映射中为每个绑定(bind)键都有一个条目。我想将多个 InputMap 条目与同一个 ActionMap 条目相关联，并使用 AbstractAction.actionPerformed(ActionEvent event) 方法中的 ActionEvent 参数来确定按下/释放/键入哪个键。我查看了 getID()，测试了 ActionEvent 是否是 KeyEvent(不是)。有没有办法做到这一点，或者我必须进行不同的重构，以便每个唯一的 ActionMap 条目设置一个参数，然后调用我的(参数化)方法？

这是有效的(但很冗长):

    getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT,0),"myRightHandler");
    getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT,0),"myLeftHandler");
    getActionMap().put("myRightHandler",new AbstractAction() {
              public void actionPerformed(ActionEvent evt) {
                  System.out.println("Typed Right Arrow");
              }
          });
    getActionMap().put("myLefttHandler",new AbstractAction() {
              public void actionPerformed(ActionEvent evt) {
                  System.out.println("Typed Left Arrow");
              }
          });

这是我想做的，但找不到魔力:

    getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT,0),"myGenericHandler");
    getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT,0),"myGenericHandler");
    getActionMap().put("myGenericHandler",new AbstractAction() {
              public void actionPerformed(ActionEvent evt) {
                  // determine what key caused the event...
                  // evt.getKeyCode() does not work.
                  int keyCode = performMagic(evt);
                  switch (keyCode) {
                      case KeyEvent.VK_RIGHT:
                          System.out.println("Typed Right Arrow");
                          break;
                      case KeyEvent.VK_LEFT:
                          System.out.println("Typed Left Arrow");
                          break;
                      default:
                          System.out.println("Typed unknown key");
                          break;
                  }
              }
          };

Answer 1

您应该首先尝试这个简单的逻辑。

getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT,0),"myRightHandler");
    getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT,0),"myLeftHandler");
    getActionMap().put("myRightHandler", new myAction("myRightHandler")); 
    getActionMap().put("myLeftHandler", new myAction("myLeftHandler")); 

    class myAction extends AbstractAction { 

        String str; 

        public myAction(String actName) {

            str = actName; 
        }

        public void actionPerformed(ActionEvent ae) { 

            switch(str) { 

                case "myRightHandler": //Here is code for 'myRightHandler'. 
                break; 

                case "myLeftHandler": //Here is code for 'myLeftHandler'. 
                break; 
                .
                .
                .
                .
                default : //Here is default Action; 
                break;
            }
        }
    } 

现在，您可以添加许多自定义组合键和操作，并通过 switch 来区分它们。