android - android policy phonewindow getSystemService 权限被拒绝

Question

我正在尝试使用

Context.getSystemService(Context.ACTIVITY_SERVICE)

获取类的topActivityinonKeyDown方法phonewindow.java。但是有人告诉我"java.lang.SecurityException: Permission Denial: getTasks()"，我该如何更改权限或者我的代码是否正确？

下面是我的一段代码

protected boolean onKeyDown(int featureId, int keyCode, KeyEvent event) {
   Context mContext;
   mContext = getContext();
   ActivityManager mActivityManager = (ActivityManager)mContext.getSystemService(Context.ACTIVITY_SERVICE);
   ComponentName mCName = mActivityManager.getRunningTasks(1).get(0).topActivity;
   String ActivityName = mCName.getClassName().toString();
   Log.d(TAG, "PackageName is " + ActivityName);
   ...
}

Answer 1

<uses-permission android:name="android.permission.GET_TASKS" >
</uses-permission>