android 返回鍵觸發後臺

轉自：http://blog.csdn.net/android_xiaoqi/article/details/8769327

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            moveTaskToBack(false);
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_BACK) {
			moveTaskToBack(false);
			return true;
		}
		return super.onKeyDown(keyCode, event);
	}

裏面的moveTaskToBack()是關鍵。