Android Application Development All-in-One For Dummies, 2nd Edition

Chapter 4

Broadcast Receivers

In This Chapter

Creating broadcast receivers

Organizing data from broadcast receivers

Restricting a receiver’s access

Chapter 3 of this minibook introduces a broadcast receiver for the purpose of running code at boot time. Here’s a summary of that chapter’s broadcast receiver news:

• When you send a broadcast, Android fires up all the receivers whose filters satisfy the intent.
• A broadcast receiver runs long enough to execute the code in the receiver’s onReceive method. A receiver has no onCreate, onDestroy, or onAnythingElse methods — only onReceive. After Android finishes executing the onReceive method’s code, the broadcast receiver becomes dormant, doing nothing until an app sends another matching broadcast.

This chapter describes broadcast receivers in more detail.

Receivers 101

This chapter’s first example contains the world’s simplest broadcast receiver. To be precise, Listing 4-1 contains the receiver class (MyReceiver, which extends BroadcastReceiver), Listing 4-2 contains code to broadcast to the receiver, and Listing 4-3 contains the example’s AndroidManifest.xml file.

Listing 4-1: A Simple Broadcast Receiver

package com.allmycode.rec1; ...