Strange warning dismissing modal view controller

Question

I'm working on iOS 6. My application has a standard navigation controller with embedded a CustomViewController. In this controller I create a modal view like this:

-(IBAction)presentModalList:(id)sender {
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    StationsListViewController *list = [storyboard instantiateViewControllerWithIdentifier:@"StationsListViewController"];
    [list setStationsData: [self.stationsData allValues]];
    [self presentModalViewController:list animated:YES];
}

The modal controller show perfectly but dismissing generates a warning. The dismiss method in this controller is:

-(IBAction)backToMap
{
    [self dismissModalViewControllerAnimated:YES];
}

The warning generated is Warning:

Attempt to dismiss from view controller < UINavigationController: 0x1ed91620 > while a presentation or dismiss is in progress!

Any clues about that?

Thanks

Related - http://stackoverflow.com/questions/1412021/iphone-crashing-when-presenting-modal-view-controller — ChrisF, Apr 03 '13 at 09:19

score 28 · Answer 1 · answered Oct 25 '12 at 11:59

28

I realise this is a late answer but maybe this will help someone else looking for a solution to this, here is what I did:

-(IBAction)backToMap
{
    if (![[self modalViewController] isBeingDismissed])
        [self dismissModalViewControllerAnimated:YES];
}

For me, i found that line of code was being called multiple times, I couldn't find out why so this was the easiest fix.

answered Oct 25 '12 at 11:59

JDx

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6

I also ran into this problem. What may be happening is that your `dimissModalViewControllerAnimated:` call may be placed in a callback (IBAction) method that is (directly or indirectly) triggered by tapping the Cancel button on the modal view -- which already handles dismissing the modal view. So this `dismissModalViewControllerAnimated:` may be a duplicate and can be removed. – smileyborg Jan 14 '13 at 18:02
1

I had a similar problem, but it was caused by a viewController being presented, then almost immediately dismissed (so dismiss was during present-animation.) So I had to check `isBeingPresented`. – Olie Feb 05 '13 at 21:20
It's weird. I think @smileyborg is onto something. But I don't see why it's dismissing seemingly automatically? All I did was an unwind action, and I don't need to dismiss it directly? – huggie Mar 04 '13 at 06:48

score 14 · Answer 2 · answered Jan 17 '13 at 23:26

Thanks JDx for getting me on the right track. I adapted it to form this solution, which will remove the warning without using functions that are deprecated in iOS 6:

-(IBAction)backToMap
{
    if (![self.presentedViewController isBeingDismissed]) {
        [self dismissViewControllerAnimated:YES completion:^{}];
    }
}

score 0 · Answer 3 · answered May 14 '13 at 19:31

I found this approach to be unreliable - say one case in five I'd still see the error.

My solution was to use the completion block to set a flag which controls whether or not it's safe to dismiss - that way you don't need to check whether or not the view is being dismissed.

-(IBAction)presentModalView:(id)sender {
    :
    self.canDismiss = NO;
    [self presentViewController:aVC animated:YES completion:^{ 
      self.canDismiss = YES; 
     }];
    :
}

In the bit of code where the dismiss occurs, just check the flag:

-(void)dismisser {
    :
    if (self.canDismiss) {
      [self dismissViewControllerAnimated:YES completion:nil];
    }
    :
}

Hey presto, no more errors!

score 0 · Accepted Answer · edited Dec 20 '13 at 10:50

0

Targeting iOS6, this is what worked for me:

if (![self.presentedViewController isBeingDismissed]) 
    [self.presentedViewController dismissViewControllerAnimated:YES
                                                     completion:nil];

edited Dec 20 '13 at 10:50

staticVoidMan

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answered Aug 24 '13 at 11:55

Yoni Hassin

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score 0 · Answer 5 · edited Dec 20 '13 at 10:44

0

You can do whatever you want after the completion of the dismiss method as:

-(IBAction)backToMap
{
    [self dismissViewControllerAnimated:YES
                             completion:^{
                                 //Do something here
                             }];
}

edited Dec 20 '13 at 10:44

Robert

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answered Oct 24 '13 at 17:35

gdm

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Strange warning dismissing modal view controller

5 Answers5