Android：拦截 onKeyDown() 和 onKeyUp()

Question

我想拦截来自硬件键盘的按键事件。例如，当用户按下“a”时，我不希望它写在 EditText 中。因此，当按下并释放“a”键时我返回 true，但无论如何它都写在 EditText 中。怎么了？

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    switch (keyCode) {
        case KeyEvent.KEYCODE_A:
            //Here it logs correct, but the letter appears in the EditText anyway
            Log.d("Textboard","A");
            return true;

        default:
            return super.onKeyDown(keyCode, event);
    }
}

@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
    switch (keyCode) {
        case KeyEvent.KEYCODE_A:
            //Here it logs correct, but the letter appears in the EditText anyway
            Log.d("Textboard","A");
            return true;

        default:
            return super.onKeyUp(keyCode, event);
    }
}

Answer 1

活动的onKeyXXX()调用晚于EditText的onKeyXXX()。

如果你想拦截它，只需覆盖dispatchKeyEvent()。