java - KeyEvent.getKeyCode() 始终返回零

Question

我正在我的小学校项目中研究暂停键，但由于某种原因它无法工作。使用此代码:

     public void keyTyped(KeyEvent me) { //ESCAPE PLS WORK ... 
        code = me.getKeyCode();
        System.out.println(code);
}

出于某种原因，“代码”始终保持为零。我尝试将其放在不同的空隙中(按下/释放等)，但它仍然不起作用。可能是什么原因？

Answer 1

这就是javadoc说的是getKeyCode()

Returns: the integer code for an actual key on the keyboard. (For KEY_TYPED events, the keyCode is VK_UNDEFINED.)

并且VK_UNDEFINED的值为零。

javadoc还说:

public static final int KEY_TYPED

The "key typed" event. This event is generated when a character is entered. In the simplest case, it is produced by a single key press. Often, however, characters are produced by series of key presses, and the mapping from key pressed events to key typed events may be many-to-one or many-to-many.

所以也许您正在寻找错误的关键事件类型。也许应该查看 KEY_PRESSED 或 KEY_RELEASED 事件，而不是 KEY_TYPED 事件。