Back button handling from a view in both present and push

Question

I have a UIViewControllerC which is call from two another UIViewcontroller

ViewControllerA ViewControllerB

From ViewControllerA to go to UIViewControllerC i have to make it presentviewcontroller

 UIViewControllerC *vc = [self.storyboard instantiateViewControllerWithIdentifier:@"UIViewControllerC"];
    [vc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
    vc.tagfrom=@"present";
    [self presentViewController:vc animated:NO completion:nil];

From ViewControllerB to go to UIViewControllerC i have to make it push view

UIViewControllerC *vc = [self.storyboard instantiateViewControllerWithIdentifier:@"UIViewControllerC"];
        [vc setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
        vc.tagfrom=@"push";
        [self.navigationController pushViewController:vc animated:YES];

Now i have to back from both view on back button i check tagfrom condition and handle it

-(IBAction)backBtn:(id)sender
{
 if ([tagfrom isEqualToString:@"present"])
  {
    [self dismissViewControllerAnimated:NO completion:nil];
}
else
{
[self.navigationController popViewControllerAnimated:YES];
}

} 

Which working fine in both senerio, but sometimes my push view behaves like presentmodelveiw, and having no transition effects in it, please help me to resolve it

Answer 1

First of all, you don't need tagfrom property on your UIViewController subclass.

A UIViewController instance has a property called presentingViewController which will let you know about the viewController ( A in your case ) that presented current viewController ( C in your case ).

-(IBAction)backBtn:(id)sender
{
   if (nil != self.presentingViewController) {
      [self dismissViewControllerAnimated:NO completion:nil];
   }
   else {
      [self.navigationController popViewControllerAnimated:YES];
   }
} 

Second, modalTransitionStyle is supposed to work with only presentation and NOT push / pop transitions. If you are using this with push / pop, the behavior is undefined because it is not meant to be used there.