Android Application Developing

If you worked with programming language like C, C++ or Java. That means you know that program is start with the main() function.  There is a sequence of callback methods that start up an activity and a sequence of callback methods that tear down an activity as shown in Activity life cycle diagram. The Activity class defines the following call backs i.e. events. You don't need to implement all the callbacks methods. You only need to understand all. onCreate() onStart() onResume() onPause() onStop() onDestroy() onRestart() Following is the code of the modified main activity file  src/com.example.sample/MainActivity.java . The Log.d() method has been used to generate log messages. package com . example . sample ; import android . os . Bundle ; import android . app . Activity ; import android . util . Log ; public class MainActivity extends Activity { String msg = "Android : " ; @Override public void onCreate ( ...

Broadcast Receivers   simply respond to broadcast messages from other applications or from the system itself. These messages are also called as events or intents. There are following two important steps to make BroadcastReceiver works for the system broadcasted intents − ·         Creating the Broadcast Receiver. ·         Registering Broadcast Receiver A broadcast receiver is implemented as a subclass of   BroadcastReceiver   class and overriding the onReceive() method where each message is received as a   Intent   object parameter. Registering Broadcast Receiver An application listens for specific broadcast intents by registering a broadcast receiver in  AndroidManifest.xml  file. Consider we are going to register  MyReceiver  for system generated event ACTION_BOOT_COMPLETED which is fired by the system once the Android system has completed the boot pr...