java - 具有焦点的 KeyListener 不起作用

Question

我正在向我的代码添加一个关键监听器，但它没有响应。我不知道这个问题是否多余，但有关类似问题的其他问题都说我应该关注该组件。然而，正如你在这里看到的，我已经尝试这样做，但没有成功。我还运行了一个线程来渲染我的(非常糟糕的)游戏，这可能是一个问题，但同样，我只是不知道。

private GamePanel() {

        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); //get screen dimensions. 

        myImage = new BufferedImage((int) screenSize.getWidth(), (int) screenSize.getHeight(), BufferedImage.TYPE_INT_RGB);
        myBuffer = myImage.getGraphics();
        Player p = new Player(400, 500);
        p.draw(myBuffer);
        abc = new Player(400, 500);
        this.addKeyListener(new Key());
        setFocusable(true);
        this.requestFocus();

    }
public void init() {
    JFrame frame = new JFrame("im bad at coding");
    frame.setLocation(0, 0);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setContentPane(this);
    frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
    frame.setUndecorated(false);
    frame.setVisible(true);
    //ive tried to request focus and set focusable here, but no results
    new Thread(this).start(); 

}

Answer 1

我认为这可能是由于以下原因之一

A) Not initializing your Game object at all when creating the JFrame
B) Not properly embedding your key listener 

试试这个:

public static void main(String[] args) {
    GamePanel panel = new GamePanel(); //Call your init methods to initialize the panel only, not the jframe
    //Initialize the key listener object either implemented in the game panel itself, or initialized inside of the panel
    new Thread(panel).start(); 
    JFrame frame = new JFrame("im actually not that bad at coding");
    frame.setLocation(0, 0);
    frame.add(panel);
    frame.addKeyListener(panel.getKeyListener()); //Or addListener, i am doing this not on an IDE
    frame.setDefaultCloseOperation(JFrame.BLOW_UP_SYSTEM_ON_EXIT);
    //Optional, just click the frame: frame.setFocus(true);
    frame.pack();
    frame.setVisible(true);
}