Java键绑定

我需要绑定所有的箭头键来执行相同的功能，但每次都要获取按下的键。目前，只有通过以下按钮按下右箭头键时，我才有

DoneImg.getInputMap(JLabel.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "UpArrow");

Action MvRight = new AbstractAction()
{
     public void actionPerformed(ActionEvent e)
     {
           //Do whatever here
     }
};
DoneImg.getActionMap().put("RightArrow", MvRight);

但我需要像这样的东西

DoneImg.getInputMap(JLabel.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "RightArrow");
     DoneImg.getInputMap(JLabel.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "LeftArrow");
     DoneImg.getInputMap(JLabel.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "DownArrow");
     DoneImg.getInputMap(JLabel.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "UpArrow");

     Action MvAll = new AbstractAction()
         {
                 public void actionPerformed(ActionEvent e)
              {
                  if (e.keypressed == "LeftArrow")
                         {System.out.println("The left arrow was pressed!");}
                  if (e.keypressed == "RightArrow")
                         {System.out.println("The right arrow was pressed!");}
                  //and so forth
              }
                 };
     DoneImg.getActionMap().put("RightArrow", MvAll);
     DoneImg.getActionMap().put("LeftArrow", MvAll);
     DoneImg.getActionMap().put("UpArrow", MvAll);
     DoneImg.getActionMap().put("DownArrow", MvAll);

---

您所问的实际上是违反直觉的，并且与密钥绑定API的设计背道而驰

其目的是为每个按键行程提供一个单独的工作单元。在我看来，这意味着每个箭头键都应该有单独的操作

它使遵循逻辑、进行更改、根据需要规避操作变得更加容易

但是，我是谁，说什么是对的呢

如果你看不到你的方法，一种简单的方法是给每个动作分配一个“命令”，然后在触发

actionPerformed

时询问

public TestKeyBindings02() {
    JPanel panel = new JPanel();
    InputMap im = panel.getInputMap(JPanel.WHEN_IN_FOCUSED_WINDOW);
    ActionMap am = panel.getActionMap();

    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "RightArrow");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "LeftArrow");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "UpArrow");
    im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "DownArrow");

    am.put("RightArrow", new ArrowAction("RightArrow"));
    am.put("LeftArrow", new ArrowAction("LeftArrow"));
    am.put("UpArrow", new ArrowAction("UpArrow"));
    am.put("DownArrow", new ArrowAction("DownArrow"));
}

public class ArrowAction extends AbstractAction {

    private String cmd;

    public ArrowAction(String cmd) {
        this.cmd = cmd;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (cmd.equalsIgnoreCase("LeftArrow")) {
            System.out.println("The left arrow was pressed!");
        } else if (cmd.equalsIgnoreCase("RightArrow")) {
            System.out.println("The right arrow was pressed!");
        } else if (cmd.equalsIgnoreCase("UpArrow")) {
            System.out.println("The up arrow was pressed!");
        } else if (cmd.equalsIgnoreCase("DownArrow")) {
            System.out.println("The down arrow was pressed!");
        }
    }
}

---

您无权访问导致执行操作的按键。因此，您需要创建4个动作，并向该动作传递一个参数。比如：

class SomeAction extends AbstractAction
{
    public SomeAction(String name)
    {
        putValue(Action.NAME, name);
        putValue(ACTION_COMMAND_KEY, "Command: " + name);
    }

    public void actionPerformed(ActionEvent e)
    {
        System.out.println("Name: " + getValue(Action.NAME) );
        System.out.println(e.getActionCommand());
    }
}

将操作添加到ActionMap中，如下所示：

DoneImg.getActionMap().put("RightArrow", new SomeAction("RightArrow"));
DoneImg.getActionMap().put("LeftArrow", new SomeAction("LeftArrow"));
DoneImg.getActionMap().put("UpArrow", new SomeAction("UpArrow"));
DoneImg.getActionMap().put("DownArrow", new SomeAction("DownArrow"));

---

因此，您共享相同的基本功能，但只需使用标识符标识每个操作。

您已经发布了所需内容，但我们需要了解更多。例如，你被困在哪里？什么不起作用？在我的答案中可以找到一个键绑定的例子。关于这个问题的一个问题是：我正在使用一个JFrame创建一个游戏，里面有一个JPanel。我还应该把钥匙绑在面板上吗？还是我应该把它放在框架上？就个人而言，你应该使用游戏的顶部容器。您应该避免从顶级容器（如

JFrame

）扩展，而是将应用程序容器化为

JPanel

，这样您可以更好地控制应用程序的部署方式。谢谢，MP。当我试图解决作为箭头键的ActionEvents的KeyEvents的混乱时，这让我的生活变得简单多了。