Passing Value of Asynctask in Fragment -

i have been working passing result created onpostexecute of asynctask in fragment. know how in activity, ((myactivity)context).somemethod(); how can in fragment?

i ((myfragment)contextofasynctask).methodinfragment() gives me error "cannot cast context myfragment".

here code in asynctask

class asyncmethod extends asynctask{

arraylist<myobject> myvar= new arraylist<myobject>(); string result; listview lv; context contextofasynctask;   public asyncmethod(context xc, listview xl){     contextofasynctask= xc;     lv = xl;  }  @override protected void onpreexecute() { }  @override protected void doinbackground(void...param) {     httpclient httpclient = new defaulthttpclient();              httppost httppost = new httppost(http://www.myurl.com/something.php);              httpresponse httpresponse = httpclient.execute(httppost);              httpentity httpentity = httpresponse.getentity();              result = entityutils.tostring(httpentity);            return null; //everything working fine here, , can value }  @override protected void onpostexecute(void res) {              //it not work here     ((myfragment)contextofasynctask).methodinfragment(result); }