In my app I have a BroadcastReceiver
that is launched as a component through a <receiver>
tag, filtering android.net.conn.CONNECTIVITY_CHANGE
intents.
My goal is simply to know when a Wifi connection was established, so what I am doing in onReceive()
is this:
NetworkInfo networkInfo = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if(networkInfo.getType() == ConnectivityManager.TYPE_WIFI && networkInfo.isConnected()) {
// Wifi is connected
}
It works fine, but I always seem to get two identical intents within about one second when a Wifi connection is established. I tried to look at any info I could get from the intent, the ConnectivityManager
and WifiManager
, but I can't find anything that distinguishes the two intents.
Looking at the log, there is at least one other BroadcastReceiver
that also receives the two identical intents.
It is running on a HTC Desire with Android 2.2
Any idea why I seem to get a "duplicated" intent when Wifi connects or what the difference between the two might be?
NOTE: For a recent, up-to-date answer, see this one below!
After a lot of googling and debugging, I believe this is the correct way to determine if Wifi has connected or disconnected.
The onReceive()
method in the BroadcastReceiver:
public void onReceive(final Context context, final Intent intent) {
if(intent.getAction().equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)) {
NetworkInfo networkInfo =
intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
if(networkInfo.isConnected()) {
// Wifi is connected
Log.d("Inetify", "Wifi is connected: " + String.valueOf(networkInfo));
}
} else if(intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
NetworkInfo networkInfo =
intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if(networkInfo.getType() == ConnectivityManager.TYPE_WIFI &&
! networkInfo.isConnected()) {
// Wifi is disconnected
Log.d("Inetify", "Wifi is disconnected: " + String.valueOf(networkInfo));
}
}
}
Together with the following receiver element in AndroidManifest.xml
<receiver android:name="ConnectivityActionReceiver"
android:enabled="true" android:label="ConnectivityActionReceiver">
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
<action android:name="android.net.wifi.STATE_CHANGE"/>
</intent-filter>
</receiver>
Some explanation:
When only considering ConnectivityManager.CONNECTIVITY_ACTION
, I always get two intents containing identical NetworkInfo instances (both getType() == TYPE_WIFI and isConnected() == true) when Wifi connects - the issue described in this question.
When only using WifiManager.NETWORK_STATE_CHANGED_ACTION
, there is no intent broadcasted when Wifi disconnects, but two intents containing different NetworkInfo instances, allowing to determine one event when Wifi is connected.
NOTE: I've received one single crash report (NPE) where the intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO)
returned null. So, even if it seems to be extremely rare to happen, it might be a good idea to add a null check.
Cheers, Torsten
If you're listening on WifiManager.NETWORK_STATE_CHANGED_ACTION
you'll receive this twice because there are 2 methods in the NetworkInfo
isConnectedOrConnecting()
isConnected()
First time isConnectedOrConnecting()
returns true
and isConnected()
false
Second time isConnectedOrConnecting()
and isConnected()
return true
Cheers
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