multithreading - UI Thread block when starting zxing-android-embedded -

so used https://github.com/journeyapps/zxing-android-embedded embedd barcode scanner app. problem takes while start, 2 4 seconds. in time ui hangs, added , asynctask , ui doesn't hang anymore, progressdialog added asychtask not show. when add thread.sleep doinbackground dialog show hangs again when thread.sleep over. have idea how let user know scanner loading?

class loadscanner extends asynctask<void, void, void> {      @override     protected void onpreexecute(){         progress = new progressdialog(mainactivity.this);         progress.settitle("loading");         progress.setmessage("wait while loading scanner...");         progress.setcancelable(false);         progress.setindeterminate(true);         progress.show();     }      @override     protected void doinbackground(void... params) {         integrator = new intentintegrator(mainactivity.this);         integrator.setdesiredbarcodeformats(intentintegrator.one_d_code_types);         integrator.setwide();         integrator.setorientation(activityinfo.screen_orientation_sensor);         try {             thread.sleep(100);         } catch (interruptedexception e) {             e.printstacktrace();         }         integrator.initiatescan();         return null;     }      @override     protected void onpostexecute(void result) {         progress.dismiss();     } } 

move spinner code out of asynctask. put before call .execute on async task.