Android Competency Center

Hello,

Now we are going to learn how to start a service at boot time, i.e. to start our service when device starts up.

First we have to create a BroadcastReceiver which will be started when boot completes as

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class MyStartupIntentReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
}
}

onRecieve will be first called when the BroadcastReceiver MyStartupIntentReceiver starts.

Next make an entry of this receiver in AndroidManifest.xml as

<receiver android:name="MyStartupIntentReceiver">
<intent-filter>
<action
android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.HOME" />
</intent-filter>
</receiver>

Here in intent filter we have declared the action as android.intent.action.BOOT_COMPLETED , so that this receiver and intent with action android.intent.action.BOOT_COMPLETED

Now this receiver will be intimated when boot completes

Next if we want to start a service then the procedure is as follows

Create a Service as

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class MyService extends Service {

	@Override
	public IBinder onBind(Intent intent) {

		return null;

	}

	@Override
	public void onCreate() {
		super.onCreate();

		Toast.makeText(this, "Service Created", Toast.LENGTH_LONG).show();

	}

	@Override
	public void onDestroy() {
		super.onDestroy();

		Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();

	}

	@Override
	public void onStart(Intent intent, int startId) {

		super.onStart(intent, startId);

		Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();

	}
}

Make an entry of this service in AndroidManifest.xml as

<service android:name="MyService">
<intent-filter>
<action
android:name="com.wissen.startatboot.MyService" />
</intent-filter>
</service>

Now start this service in the BroadcastReceiver MyStartupIntentReceiver’s onReceive method as

	public void onReceive(Context context, Intent intent) {
		Intent serviceIntent = new Intent();
		serviceIntent.setAction("com.wissen.startatboot.MyService");
		context.startService(serviceIntent);

	}

Next you can write the code that you want to execute when device boots up in the BroadcastReceiver or in the Service

Android Android, boot, boot complete, BroadcastReceiver, service

Hello,

Today we are going to learn how to access  sensor and retrieve data from it.

First, to access device’s sensors we have to use  Class SensorManager(android.hardware.SensorManager). that lets you access the device’s sensors

http://developer.android.com/reference/android/hardware/SensorManager.html

To get SensorManager we have to use getSystemService(ServiceName)

It returns handle to a system level service.Hence we get handle to SensorManager as below

//Declare Sensor Manager class object

private SensorManager mSensorManager;

//Next get the handle to the Sensor service

mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);

Next declare a listener  for receiving notifications from the SensorManager when sensor values have changed as.

private final SensorListener sensorListener = new SensorListener(){
public void onSensorChanged(int sensor, float[] values)
{

//Retrieve the values from the float array values which contains sensor data
Float dataX = values[SensorManager.DATA_X];

Float dataY = values[SensorManager.DATA_Y];

Float dataZ = values[SensorManager.DATA_Z];

//Now we got the values and we can use it as we want

Log.i("X - Value",""+dataX);

Log.i("Y - Value",""+dataY);

Log.i("Z - Value",""+dataZ);

}

public void onAccuracyChanged(int sensor, int accuracy) {}

};

For above listener to be notified of changed value we have to register it . We can register it in onResume as

protected void onResume() {

super.onResume();

mSensorManager.registerListener(sensorListener,
SensorManager.SENSOR_ORIENTATION,
SensorManager.SENSOR_DELAY_GAME);
}

The syntax of register listener is as

SensorManager.registerListener(SensorListener listener, int sensors, int rate)

We can unregister the sensorlistener in onStop as

protected void onStop() {

super.onStop();

mSensorManager.unregisterListener(sensorListener);
}

Android accelerometer, Android, orientation, sensor, SensorManager, SENSOR_SERVICE

We were invited by Pune Google Technology User Group (GTUG) to introduce developers to Android platform for application development. Our presentation went well and developers present liked it. Here is the presentation.

Android