Java外部Keylistener没有响应

Question

我想听键盘输入，但没有KeyCode，但KeyListener必须在外部类中

Main.java：

public class Main {

    public static void main(String args[]){

        new Spielfeld("Spielfeld");
        new KeyEventListener();
    }

}

KeyEventListener.java

public class KeyEventListener implements KeyListener{

public KeyEventListener(){

}

@Override
public void keyPressed(KeyEvent e) {

    System.out.println(e.getKeyCode());

}

@Override
public void keyReleased(KeyEvent arg0) {}

@Override
public void keyTyped(KeyEvent arg0){}

}

抱歉，我是Java新手，不知道如何解决此问题...

Answer 1

您需要将keyListener添加到任何组件，例如JTextField，

这是一个很好的例子：

public class KeyEventDemo ...  implements KeyListener ... {
    ...//where initialization occurs:
        typingArea = new JTextField(20);
        typingArea.addKeyListener(this);


    ...
    /** Handle the key typed event from the text field. */
    public void keyTyped(KeyEvent e) {
        displayInfo(e, "KEY TYPED: ");
    }

    /** Handle the key-pressed event from the text field. */
    public void keyPressed(KeyEvent e) {
        displayInfo(e, "KEY PRESSED: ");
    }

    /** Handle the key-released event from the text field. */
    public void keyReleased(KeyEvent e) {
        displayInfo(e, "KEY RELEASED: ");
    }

听众的更多信息： 这里