java - Unable to execute Asynctask inside the setOnClickListener -


i'm having error on line -> new gethttpresponse(this).execute();

it doens't have error when put outside button

i got code http://www.android-examples.com/create-dynamic-listview-using-json-parsing-php-mysql/ , added button can refreshed when database updated

 public class mainactivity extends activity {      listview listcollege;     progressbar procollagelist;     button bton;     @override     protected void oncreate(bundle savedinstancestate)  {     super.oncreate(savedinstancestate);     requestwindowfeature(window.feature_no_title);     setcontentview(r.layout.activity_main);     bton = (button) findviewbyid(r.id.button);     listcollege = (listview)findviewbyid(r.id.listcollege);     procollagelist = (progressbar)findviewbyid(r.id.procollagelist);     new gethttpresponse(this).execute();      bton.setonclicklistener(new onclicklistener() {         @override         public void onclick(view view) {             toast.maketext(mainactivity.this, "list refreshed", toast.length_short).show();             new gethttpresponse(this).execute();         }}); }        private class gethttpresponse extends asynctask<void, void, void>      {         private context context;         string result;         list<benedict.com.listviewpractice.cources> collegelist;         public gethttpresponse(context context)         {             this.context = context;         }          @override         protected void onpreexecute()          {             super.onpreexecute();         }          @override         protected void doinbackground(void... arg0)          {             httpservice httpservice = new httpservice("http://10.0.2.2/courses.php");             try              {                 httpservice.executepostrequest();                  if(httpservice.getresponsecode() == 200)                 {                     result = httpservice.getresponse();                     log.d("result", result);                     if(result != null)                     {                         jsonarray jsonarray = null;                         try {                             jsonarray = new jsonarray(result);                              jsonobject object;                             jsonarray array;                             benedict.com.listviewpractice.cources college;                             collegelist = new arraylist<benedict.com.listviewpractice.cources>();                             for(int i=0; i<jsonarray.length(); i++)                             {                                 college = new benedict.com.listviewpractice.cources();                                 object = jsonarray.getjsonobject(i);                                  college.cources_name = object.getstring("cource_name");                                 college.cources_description = object.getstring("cources_description");                                  collegelist.add(college);                             }                         }                         catch (jsonexception e) {                             // todo auto-generated catch block                             e.printstacktrace();                         }                     }                 }                 else                 {                     toast.maketext(context, httpservice.geterrormessage(), toast.length_short).show();                 }             }              catch (exception e)              {                 // todo auto-generated catch block                 e.printstacktrace();             }             return null;         }          @override         protected void onpostexecute(void result)           {             procollagelist.setvisibility(view.gone);             listcollege.setvisibility(view.visible);             if(collegelist != null)             {             listadapter adapter = new listadapter(collegelist, context);             listcollege.setadapter(adapter);             }         }     } }

inside onclicklistener, this represents instance of onclicklistener, not context object expected, this should mainactivity.this.

new gethttpresponse(mainactivity.this).execute();

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