WiFi state change Listener (Receiver) Android

There is no listener like OnClick listener to listen to WiFi status/state change during an activity.

To Listen to WiFi state change we have a to register a receiver that receives WiFi state change.

The following code helps you to listen to WiFi status change while running app in foreground

1.Add these permissions  to your Manifest file.

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
These are normal (PROTECTION_NORMAL) permissions. So you don't need check at runtime.

2. Create a receiver that has to run on receiving WiFi state change

     private BroadcastReceiver receiver = new BroadcastReceiver() {            public void onReceive(Context context, Intent intent) {                NetworkInfo info = getNetworkInfo(context);                if (info != null && info.isConnected()) {                    //Todo code to execute if wifi connected                } else {nbsp;                  //Todo code to execute if wifi disconnected                }            }        };        private NetworkInfo getNetworkInfo(Context context) {               ConnectivityManager connManager = (ConnectivityManager)                         context.getSystemService(Context.CONNECTIVITY_SERVICE);               return connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);        }

3. create a boolean that check the registration of receiver.

This is required to avoid registering or deregistering the receiver multiple times.      private boolean isReceiverRegistered = false;

4. Register your receiver in onResume method of the activity.

      protected void onResume() {          super.onResume();          if (!isReceiverRegistered) {              isReceiverRegistered = true;              registerReceiver(receiver, new IntentFilter("android.net.wifi.STATE_CHANGE")); // IntentFilter to wifi state change is "android.net.wifi.STATE_CHANGE"          }       }

5. UnRegister the receiver when ever you pause the activity to avoid leak of receiver.

      protected void onPause() {          super.onPause();          if (isReceiverRegistered) {              isReceiverRegistered = false;              unregisterReceiver(receiver);          }       }

How to start/ launch application at boot time Android

If you want your app to start-up automatically when Android boots up you need to the following

  

Step 1:
 add the permission android.permission.RECEIVE_BOOT_COMPLETED  to your Manifest file.
        <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

Step 2: register receiver in your application in manifest.

        <receiver
          android:name=".YourReceiverName" <!-- name of your class that extends BroadcastReceiver -->
          android:enabled="true"          android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
          <intent-filter>
              <action android:name="android.intent.action.BOOT_COMPLETED" />
             <action android:name="android.intent.action.QUICKBOOT_POWERON" />
              <category android:name="android.intent.category.DEFAULT" />
          </intent-filter>
     </receiver>

     Note: this code should be inside of <application  ...> </application> of manifest file

Step 3: Create the class that extends BroadcastReceiver

public class YourReceiverName extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        //Your code that has to run on start up/ boot time
    }
}