objective c - Show, activate and stop indetermined progress indicator -

i'm having issues showing progress indicator whenever button clicked, , stop , hide indicator when nstask completed.

this should timeline: 1- button clicked 2- shows progress indicator (from hidden state) 3- activates progress indicator 4- activate associated nstask 5- continue showing indicator until nstask completed 6- after completion of nstask, hide progress indicator.

i know how progress indicator animate etc. not know how combine these nstask completing thing..

thanks in advance!

use nstask's terminationhandler property set block execute when task terminates. in block stop/hide progress indicator.

addendum (see comments)

in rough outline:

nstask *mytask = ...; nsprogressindicator *myindicator = ...;  mytask.terminationhandler = ^(nstask *thetask) { [myindicator stopanimation:nil]; }; 

note handler passed nstask in case needs access information it. nil passed sender stopanimation: - pass self cause retain cycle , object invoking method isn't important.