android - How to get network status changes with BroadcastReceiver? -

when change wi-fi 3g or vice versa asynctask cause error. want trace , restart loading progress(or stop , proceed asynctask if possible) when happens. looked on google , find broadcastreceiver onreceive called when happens. problem still don't exact moment when happens.

oncreate

    registerreceiver(mconnreceiver,new intentfilter(connectivitymanager.connectivity_action)); 

asynctask point of error(it's called on httpclient line):

@override protected string doinbackground(string... params) {     httpclient httpclient = new defaulthttpclient();     httppost httppost = new httppost(params[0]);     try     {         if(!iscancelled())//i have set after found error         {             httpresponse response = httpclient.execute(httppost);             jsonresult = inputstreamtostring(                     response.getentity().getcontent()).tostring();         }     } 

the broadcastreceiver

private broadcastreceiver mconnreceiver = new broadcastreceiver() {     @override     public void onreceive(context context, intent intent)     {         boolean noconnectivity = intent.getbooleanextra(connectivitymanager.extra_no_connectivity, false);         networkinfo changes = intent.getparcelableextra(connectivitymanager.extra_network_info);          log.w("current", "" + changes);         if(noconnectivity)         {             task.cancel(true);             task2.cancel(true);             task3.cancel(true);         }         log.w("taskiscanceled","" + task.iscancelled());      } }; 

so have 2 problems tracing event of error , restarting or stopping , proceeding asynctaskes. have 3 asynctaskes take turns.

when switch 3g wi-fi noconnectivity boolean returns have connection. while when go wi-fi 3g first returns dont , shortly after have(so connected).

you can use reflections monitor mobile data changes.

public class networkstatereceiver extends broadcastreceiver {      @override     public void onreceive(context context, intent intent) {         if(intent.getextras() != null){             final connectivitymanager mconnectivitymanager = (connectivitymanager)context.getsystemservice(context.connectivity_service);             boolean mobiledataenabled = false;              try{                 class cmclass = class.forname(mconnectivitymanager.getclass().getname());                 method method = cmclass.getdeclaredmethod("getmobiledataenabled");                 method.setaccessible(true); // make method callable                 mobiledataenabled = (boolean)method.invoke(mconnectivitymanager);             } catch(exception e){                 return;             }             toast.maketext(backroundservice.this, "data state changed", toast.length_long).show();                     }     }  }