BroadcastReceiver in Android: 1. How to respond to Intent broadcast 2. How to intercept incoming SMS 3. How to put an application in device startup

1. Android Application Development
Broadcast Receiver
Click to edit Master subtitle style
Ahsanul Karim
ahsanul.karim@sentinelbd.com
Sentinel Solutions Ltd.
http://www.sentinelbd.com
5/21/11

2. Application Building Blocks
ly Corresponding to one screen.
IntentReceiver Service Activity ContentProvider
ns or status changes.that runs in up your process. applications to share data.
Faceless task Can wake the background.
Enable
5/21/11

3. Android Application Anatomy
Activities Services
1. Provides User Interface 1. No User Interface
2. Usually represents a Single 2. Runs in Background
Screen
3. Extends the Service Base
3. Can contain one/more Views Class
4. Extends the Activity Base
class
Application= Set of Android Components
Intent/Broadcast Receiver Content Provider
1. Receives and Reacts to 1. Makes application data
broadcast Intents available to other apps
2. No UI but can start an 2. Data stored in SQLite database
Activity 3. Extends the ContentProvider
Base class
3. Extends the BroadcastReceiver
5/21/11 Base Class

4. Broadcast Receivers
1. A broadcast receiver is a component that responds to system-wide
Broadcast announcements.
1. Many broadcasts originate from the system—for example, a
Broadcast announcing that the screen has turned off, the battery
is low, or a picture was captured or an SMS is received.
1. Applications can also initiate broadcasts—for example, to let other
Applications know that some data has been downloaded to the
device and is available for them to use.
1. Although broadcast receivers don't display a user interface, they may
create a status bar notification to alert the user when a
broadcast event occurs.
1. More commonly, though, a broadcast receiver is just a "gateway" to
other components and is intended to do a very minimal amount of
work. For instance, it might initiate a service/or start an activity to
perform some work based on the event.
5/21/11

5. Android Application Anatomy
Activity 1 Activity 2
UI
Service BroadcastReceiver
Intents
1. Directed Intents
2. Broadcast Intents OS
BIG PICTURE
5/21/11

6. Broadcast Receivers
1. We’ll use a Broadcast Receiver to capture SMS receive event
2. We capture the SMS receive event and launch an Activity to show the sms and give user
an option to reply the SMS
Activity
OS BroadcastReceiver
5/21/11

7. Broadcast Receivers
1. Create a new project BroadcastReceiverDemo
2. A broadcast receiver is implemented as a subclass of BroadcastReceiver and each
broadcast is delivered as an Intent object. In this case the intent is detected by
android.provider.Telephony.SMS_RECEIVED
To do this we’ll create a class SMSReceiver that extends BroadcastReceiver class and
define the method onReceive()
BroadcastReceiver
5/21/11

8. Broadcast Receivers (Contd.)
3. We also need to add SMSReceiver as receiver of a particular Intent (SMS received)
which is identified by android.provider.Telephony.SMS_RECEIVED
BroadcastReceiver
5/21/11

9. Broadcast Receivers (Contd.)
4. Also we have to add permission for receiving SMS
BroadcastReceiver
5/21/11

10. Broadcast Receivers (Contd.)
5. Now we run the application
6. Now we use emulator control to send sms
5/21/11

11. Sending SMS
1. Add permission in menifest.xml
2. We add the following code for sending SMS from anywhere of our application
5/21/11

12. Exercise
We’ll create a replica of SMS application of Android
1. Application will have a basic TabActivity with 3 tabs (Activities)
1. Send- will give user option to send sms (2 input fields for number and text)
All sent SMS will be saved in database
1. Inbox- (List Activity) which will fetch all received SMS from database
2. Sent- (ListActivity) which will fetch all sent SMS
1. A broadcast receiver which will receive SMS and save them to database
5/21/11