Part of my app's functionality is to scan and display a list of WiFi access points, and then connect to the one chosen by the user. I have this functionality working. Now, I also wish to be notified when the connection "goes through". This should be fairly simple, but I find myself stumbling.
I have read through various posts here at SO, and they all mention registering for WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION
or WifiManager.WIFI_STATE_CHANGED_ACTION
. However, neither of these works for me. Can anyone spot any mistake in this code? (I am leaving out the parts which do the scan and stuff)
Expected behavior: As soon as the connection is successful (i.e, when I see the "connected" icon on the notification bar), the broadcast should be received and I should see the toast.
Observed behavior: The broadcast is received when the app first starts, and whenever I switch back to it (i.e, whenever onResume()
is called; or I suspect, whenever I register for the intent)
public class WifiScanActivity extends Activity {
WifiManager mainWifi;
WifiReceiver mWifiReceiver;
IntentFilter mIntentFilter;
private final static String TAG = "WifiScanActivity";
public static final String INTENT_FOR_WIFI_CONNECTED =
WifiManager.WIFI_STATE_CHANGED_ACTION;
// public static final String INTENT_FOR_WIFI_CONNECTED =
// WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
mWifiReceiver = new WifiReceiver();
mIntentFilter = new IntentFilter();
mIntentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
mIntentFilter.addAction(INTENT_FOR_WIFI_CONNECTED);
registerReceiver(mWifiReceiver, mIntentFilter);
mainWifi.startScan();
}
protected void onPause() {
unregisterReceiver(mWifiReceiver);
super.onPause();
}
protected void onResume() {
registerReceiver(mWifiReceiver, mIntentFilter);
super.onResume();
}
class WifiReceiver extends BroadcastReceiver {
public void onReceive(Context c, Intent intent) {
Log.d(TAG,
"In WifiReceiver: Broadcast Received = " + intent.getAction());
if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(intent
.getAction())) {
// Display the ListView and connect to the selected AP
} else if (INTENT_FOR_WIFI_CONNECTED.equals(intent.getAction())) {
if (WifiManager.WIFI_STATE_ENABLED == intent.getIntExtra(
WifiManager.EXTRA_WIFI_STATE, 0)) {
displayNetworkInfo();
}
/*if(true == intent.getBooleanExtra(
* WifiManager.EXTRA_SUPPLICANT_CONNECTED, false)){
* displayNetworkInfo();
}*/
}
}
}
private void displayNetworkInfo() {
WifiInfo wifiInfo = mainWifi.getConnectionInfo();
String ssid = wifiInfo.getSSID();
int ip = wifiInfo.getIpAddress();
String message = "Connection established.\nSSID = " + ssid
+ "; IP Address = " + Helper.displayIpAddress(ip);
Log.d(TAG, message);
Toast.makeText(this, message, Toast.LENGTH_LONG).show();
}
}
If I uncomment the code for WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION, I don't see the broadcast being received at all.
Note: I know that the connection is successful because I see the status in Android's wifi settings screen.
Ok, I figured it out. It turns out I was registering for the wrong intent. I should be using
WifiManager.NETWORK_STATE_CHANGED_ACTION
.
Here are the snippets of relevant portions of code:
mIntentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION) ;
mIntentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
public void onReceive(Context c, Intent intent) {
if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(intent.getAction())) {
NetworkInfo nwInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
if(NetworkInfo.State.CONNECTED.equals(nwInfo.getState())){//This implies the WiFi connection is through
displayNetworkInfo();
}
}
I was able to detect after adding these permissions to manifest to detect the broadcast:
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
To get the broadcast after status is being changed see this
来源:https://stackoverflow.com/questions/6595734/wifi-state-changed-action-intent-not-received-upon-connection-to-wifi-access-poi