multithreading - recyclerView.adapter on notifydatasetchanged hangs the ui android -

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• android “only original thread created view hierarchy can touch views.” 14 answers

i having trouble updating recyclerview notify data set changed, since hangs ui couple of seconds upon called. after searching on net, suggested update adapter on background thread.

 private synchronized void updateadapter() {     asynctask<void, void, void> task = new asynctask<void, void, void>() {         @override         public void doinbackground(void... params) {             adapter.notifydatasetchanged();             return null;         }     };     task.execute(); } 

and upon running line of code, app crashed error,

"only original thread created view hierarchy can touch views."

and upon searching further, suggested solution run on ui thread.

runonuithread(new runnable() {  @override  public void run() {  } }); 

which brings me initial problem. how should handle problem? appreciated. thank you.

 private synchronized void updateadapter() {     asynctask<void, void, void> task = new asynctask<void, void, void>() {         @override         public void doinbackground(void... params) {             adapter.notifydatasetchanged();             return null;         }     };     task.execute(); } 

please study asynctask doinbackground should not have ui changes .in case u performing ui changes on seperate thread in asynctask . put notifydatasetchanged on onpostexecute shown below( works on main thread ). add onpreexcute() , onpostexecute() performed on main ui , onbackground() on separate thread ( not main ui ).

 private synchronized void updateadapter() {     asynctask<void, void, void> task = new asynctask<void, void, void>() {         @override         public void doinbackground(void... params) {            // query db or perform long operations here             return null;         }          @override         onpostexecute(void.. params){              adapter.notifydatasetchanged();         }     };     task.execute(); }