怎样在安卓中实现在锁屏状态下弹出对话框，并可以震动和铃声，就像闹钟似的？

====================问题描述====================
我想要在应用弹出对话框，程序在后台运行，当达到条件后弹出对话框并有震动和铃声，但是在锁屏状态下却没反应，有什么办法解决吗？
====================解决方案1====================

//点亮屏幕
PowerManager pm = (PowerManager)getSystemService(POWER_SERVICE);
mWakelock = pm.newWakeLock(PowerManager.ACQUIRE_CAUSES_WAKEUP |PowerManager.SCREEN_DIM_WAKE_LOCK, "SimpleTimer");
mWakelock.acquire();
//.......
mWakelock.release();

点亮屏幕需要权限：
<uses-permission android:name="android.permission.WAKE_LOCK"/>
====================解决方案2====================
按照LS的方法 请求强制打开锁，会出现按Power键,系统也不会进入Sleep的现象

建议参考如下方法，让对话框在锁屏界面上方显示
onCreate方法时使用
requestWindowFeature(Window.FEATURE_NO_TITLE); //hide title
Window win = getWindow();
WindowManager.LayoutParams winParams = win.getAttributes();
winParams.flags |= (WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
| WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
| WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
setRequestedOrientation(0);

在OnResume时使用
protected void onResume() {
super.onResume();
acquireWakeLock();
}

private void acquireWakeLock() {
if (mWakelock == null) {
Log.i(TAG, "Activity begin start ");
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
mWakelock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, this.getClass().getCanonicalName());
mWakelock.acquire();
}

在onPause
protected void onPause() {
super.onPause();
......
releaseWakeLock();
}

private void releaseWakeLock() {
if (mWakelock != null && mWakelock.isHeld()) {
mWakelock.release();
mWakelock = null;
}
希望对LZ有所帮助！