requestFeature() must be called before adding the content

Question

I want to create an android application to trigger the alarm. I have a button called btnStart. When the user click the button, in 3 second, it should go to AlarmReceiverActivity.java and start play the sound.

the btnStart onclick method look like

btnStart.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            int i = 3;
            Intent intent = new Intent (MapPage.this, AlarmReceiverActivity.class);
                PendingIntent pending =
                        PendingIntent.getActivity(MapPage.this, 2, intent, 
                                            PendingIntent.FLAG_CANCEL_CURRENT);

            AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
                            am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+(i * 1000), pending);

            if (toast != null){
                toast.cancel();
            }

            toast = Toast.makeText(getApplicationContext(), "Alarm for activity is set in : "+ i +" second", toast.LENGTH_SHORT);
            toast.show();                       
            }
        });

and the AlarmReceiverActivity.java look like this

public class AlarmReceiverActivity extends Activity{
private MediaPlayer mMediaPlayer;
private PowerManager.WakeLock mWakeLock;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.alarm);

    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
    mWakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "My Wake Log");
    mWakeLock.acquire();
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN |
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
            WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON,
            WindowManager.LayoutParams.FLAG_FULLSCREEN |
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
            WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);

    Button stopAlarm = (Button) findViewById(R.id.stopAlarm);
    stopAlarm.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            mMediaPlayer.stop();
            finish();
        }
    });
    playSound (this, getAlarmUri());
}

to make this short question short, there are some method that I not state above. When I click the button, I got and error. It say that

java.lang.RunTimeException: Unable to start activity ComponentInfo{com.example.splashscreen/com.example.splashscreen.AlarmReceiverActivity}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content

Any idea on how to solve this problem ? Thank you in advance

Answer 1

Chnage the order like this..

this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN |
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
            WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON,
            WindowManager.LayoutParams.FLAG_FULLSCREEN |
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED |
            WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
super.onCreate(savedInstanceState);
setContentView(R.layout.alarm);