Step 1: Create an XML in the drawable folder and name it selected_item.xml (or any another name you want but to be suggestive). The code in this xml will be:

<shape android="http://schemas.android.com/apk/res/android" shape="rectangle"><br /> <solid color="#80000000"><br /> </solid></shape>

The color="#80000000" is transparent black.
Step 2: Create an XML again, in the drawable folder an name it not_selected.xml. The code in this xml will be:

<shape android="http://schemas.android.com/apk/res/android" shape="rectangle">
<solid color="#80ffffff">
</solid></shape>

The color="#80ffffff" is transparent white.

Step 3 Create an XML again :) in the drawable folder and name it button_selector.xml. The code in this xml will be:

<selector android="http://schemas.android.com/apk/res/android">
<item drawable="@drawable/selected" state_focused="false" state_pressed="true">
<item drawable="@drawable/not_selected">
</item></item></selector>

Step 4 In the xml file where you make the button put this:

android:background="@drawable/button_selector"

April 17, 2013

AlarmManager class provides access to the system alarm services. These allow you to schedule your application to be run at some point in the future. When an alarm goes off, the Intent that had been registered for it is broadcast by the system, automatically starting the target application if it is not already running. 

In this exercise, a scheduled alarm of 10 seconds will start a service, MyAlarmService. 

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="@string/hello"

/>

<Button

android:id="@+id/startalarm"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Start"

/>

<Button

android:id="@+id/cancelalarm"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Cancel"

/>
</LinearLayout>
AndroidAlarmService.java, the main activity

package com.shir60bhushan.AndroidAlarmService;



import java.util.Calendar;



import android.app.Activity;

import android.app.AlarmManager;

import android.app.PendingIntent;

import android.content.Intent;

import android.os.Bundle;

import android.os.SystemClock;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;



public class AndroidAlarmService extends Activity {



private PendingIntent pendingIntent;





/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.main);

    Button buttonStart = (Button)findViewById(R.id.startalarm);

    Button buttonCancel = (Button)findViewById(R.id.cancelalarm);



    buttonStart.setOnClickListener(new Button.OnClickListener(){



 @Override

 public void onClick(View arg0) {

  // TODO Auto-generated method stub



  Intent myIntent = new Intent(AndroidAlarmService.this, MyAlarmService.class);

  pendingIntent = PendingIntent.getService(AndroidAlarmService.this, 0, myIntent, 0);



           AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);



           Calendar calendar = Calendar.getInstance();

           calendar.setTimeInMillis(System.currentTimeMillis());

           calendar.add(Calendar.SECOND, 10);

           alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);

       

  Toast.makeText(AndroidAlarmService.this, "Start Alarm", Toast.LENGTH_LONG).show();

 }});



    buttonCancel.setOnClickListener(new Button.OnClickListener(){



 @Override

 public void onClick(View arg0) {

  // TODO Auto-generated method stub

  AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);

  alarmManager.cancel(pendingIntent);



           // Tell the user about what we did.

           Toast.makeText(AndroidAlarmService.this, "Cancel!", Toast.LENGTH_LONG).show();

 }});
}
}




this the MyAlarmService.java service for managing and  triggering the alarm


package com.Shir60bhushan.AndroidAlarmService;



import android.app.Service;

import android.content.Intent;

import android.os.IBinder;

import android.widget.Toast;



public class MyAlarmService extends Service {



@Override

public void onCreate() {

// TODO Auto-generated method stub

Toast.makeText(this, "MyAlarmService.onCreate()", Toast.LENGTH_LONG).show();

}



@Override

public IBinder onBind(Intent intent) {

// TODO Auto-generated method stub

Toast.makeText(this, "MyAlarmService.onBind()", Toast.LENGTH_LONG).show();

return null;

}



@Override

public void onDestroy() {

// TODO Auto-generated method stub

super.onDestroy();

Toast.makeText(this, "MyAlarmService.onDestroy()", Toast.LENGTH_LONG).show();

}



@Override

public void onStart(Intent intent, int startId) {

// TODO Auto-generated method stub

super.onStart(intent, startId);

Toast.makeText(this, "MyAlarmService.onStart()", Toast.LENGTH_LONG).show();

}



@Override

public boolean onUnbind(Intent intent) {

// TODO Auto-generated method stub

Toast.makeText(this, "MyAlarmService.onUnbind()", Toast.LENGTH_LONG).show();

return super.onUnbind(intent);

}



}





Finally Add the service declaration in the manifest file of the application

<service android:name=".MyAlarmService" />

April 09, 2013