c# - ProgressRing is not showing while the app runs -

i developing 'universal app' windows 8.1 , windows phone 8.1

i need add progressring control page, because there task takes time complete , should notify user app loading data. followed instruction on mdsn in following link:

to create indeterminate progress ring , stated need:

4. adding indeterminate progress ring

when can't estimate how work remains finish task , task block user interaction, use indeterminate progress ring. indeterminate progress ring shows animate sequence of dots moving in circle.

the problem progressring doesn't play animation of "loading", when insert prog.isactive = true; before code starts task

if comment task lines of code, plays.

xaml :

 <progressring x:name="prog" margin="435,349,388,181" fontfamily="{staticresource fontfamily6}" fontsize="25" /> 

c#:

 private void leveltap(object sender, tappedroutedeventargs e)     {         prog.isactive = true;         checknav(sender);     }  private void checknav(object sender)     {         textblock tb = sender textblock;         gamesetter game = new gamesetter();         game.level = (int)textdict[tb];         if (!levelsarr[game.level]) return;         if (!gotoleader)         {                         prog.isactive = false;             callnav(true, game);         }         else         {             prog.isactive = false;             callnav(false, game);         }         }      private void callnav(bool b,gamesetter g)     {          if(b)  frame.navigate(typeof(game8), g);         else frame.navigate(typeof(mainpage), g);     } 

note: task runs uses dictionary, windows.storage.applicationdata, , navigation page in end.

you can use code block in every function if progressing indeterminate mode open:

  #region progress ring start             await dispatcher.runasync(coredispatcherpriority.normal, () =>             {                 waiter.visibility = visibility.visible; // progress ring name waiter.             });              #endregion             await task.delay(1000);             checknav(sender); // process                #region progress ring finish             await dispatcher.runasync(coredispatcherpriority.normal, () =>             {                 waiter.visibility = visibility.collapsed; // progress ring name waiter.              });             #endregion