Animation not playing after dismissViewController iOS -

i have "aviewcontroller" root viewcontroller , have image playing animation infinite loop.

- (void)rotateimageview {      [uiview animatewithduration:1 delay:0 options:uiviewanimationoptioncurvelinear animations:^{         [self.imageviewspin settransform:cgaffinetransformrotate(self.imageviewspin.transform, m_pi_2)];     }completion:^(bool finished){         if (finished) {             [self rotateimageview];         }     }]; } 

in viewwillappear

-(void)viewwillappear:(bool)animated{     [super viewwillappear:animated];     [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(rotateimageview) name:uiapplicationwillenterforegroundnotification object:nil];     [self rotateimageview]; } 

this work great if application become active. when i'm try presentviewcontroller "cviewcontroller" [self.navigationcontroller presentviewcontroller: animated: completion:] , have button on "cviewcontroller"

[self dismissviewcontrolleranimated:yes completion:^{         [[nsnotificationcenter defaultcenter] postnotificationname:@"checkispresent" object:self];     }]; 

after returning "aviewcontroller",animation stops working. how solve issue. thank you.

edit.

work put [self rotateimage]; in method postnotification.

-(void)viewwillappear:(bool)animated{     [super viewwillappear:animated];     [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(rotateimageview) name:uiapplicationwillenterforegroundnotification object:nil];     [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(checkpresentview) name:@"checkispresent" object:nil];     [self rotateimageview]; } -(void)checkpresentview{     //ismodalview = false;     [self rotateimageview]; }