Android 响应组合键

boolean aIsDown = false;boolean qIsDown = false;@Overridepublic boolean dispatchKeyEvent(KeyEvent event) {    // TODO Auto-generated method stub    // 判断普通按键    int keyCode = event.getKeyCode();    if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN            && event.getAction() == KeyEvent.ACTION_DOWN) {        aIsDown = true;    } else if (keyCode == KeyEvent.KEYCODE_VOLUME_UP            && event.getAction() == KeyEvent.ACTION_DOWN) {        qIsDown = true;    }else if((keyCode == KeyEvent.KEYCODE_VOLUME_UP && !aIsDown)||(keyCode == KeyEvent.KEYCODE_VOLUME_DOWN && !qIsDown)){        aIsDown = false;        qIsDown = false;    }else if (aIsDown            && qIsDown            && (keyCode == KeyEvent.KEYCODE_VOLUME_UP || keyCode == KeyEvent.KEYCODE_VOLUME_DOWN)            && event.getAction() == KeyEvent.ACTION_UP) {        Toast.makeText(ActivityLogin.this, "Q + A", Toast.LENGTH_SHORT).show();        aIsDown = false;        qIsDown = false;    }else{        aIsDown = false;        qIsDown = false;    }    return super.dispatchKeyEvent(event);}