RTC_WAKEUP is not working

Question

Currently i am working on a Broadcast Receiver application, in which i am making an Alarm which should display a message after we enter the seconds. I used RTC_WAKEUP, which means it should display the message when the device is on and it is supposed to turn on the device and then display the message when the device is off. MY PROBLEM IS THAT IT RTC_WAKEUP DOESN'T ON MY DEVICE but it is working properly when device is on. i am pasting the code of my application. In my application there are two classes.

MainActivity

public class MainActivity extends Activity {


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void startAlert(View view) {
        EditText text = (EditText) findViewById(R.id.time);
        int i = Integer.parseInt(text.getText().toString());
        Intent intent = new Intent(this, MyBroadcastReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this.getApplicationContext(), 23432424, intent, 0);
        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
                + (i * 1000), pendingIntent);
        Toast.makeText(this, "Alarm set in " + i + " seconds",
                Toast.LENGTH_LONG).show();
    }
}

and other is

MyBroadcastReceiver

    public class MyBroadcastReceiver extends BroadcastReceiver {
      @Override
      public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "Jaago Mohan Pyarreee!!!!.",
            Toast.LENGTH_LONG).show();
      }
    } 

Manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcastreceiver"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />
    <uses-permission android:name="android.permission.VIBRATE"/>
    <uses-permission android:name="android.permission.WAKE_LOCK" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
         <receiver android:name=".MyBroadcastReceiver" >
        </receiver>
    </application>

</manifest>

Answer 1

RTC_WAKEUP will not switch on the screen, all it does is wakes up thee cpu so that your job is done. For the Screen to be turned on you need a FULL wakelock to be acquired.

PowerManager pm = (PowerManager)mContext.getSystemService(Context.POWER_SERVICE);
 PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK
                                      | PowerManager.ON_AFTER_RELEASE,
                                      "wakeup");
 wl.acquire();
 // ... do work...
//show toask
 wl.release();