UIImagePickerController not presenting in iOS 8

Question

Is anyone else having an issue with UIImagePickerController in iOS 8? The method below works perfectly well in iOS 7 on an iPad, but I get the following error when I run this in XCode 6 (Beta 3 or 4) when I try to present the picker (last line). If it matters, the selection of the sourceType is coming from an alertView that is presented in the same place.

Warning: Attempt to present <UIImagePickerController: 0x7c0ae400>  on <CAGUCreateContactViewController: 0x7bf61a00> which is already presenting (null) 

Method to open imagePicker.

- (void)openPhotoPicker:(UIImagePickerControllerSourceType)sourceType {     if ([UIImagePickerController isSourceTypeAvailable:sourceType]) {         NSArray *availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:sourceType];         if ([availableMediaTypes containsObject:(NSString *)kUTTypeImage]) {             UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];             imagePickerController.modalPresentationStyle = UIModalPresentationFullScreen;             imagePickerController.sourceType = sourceType;             imagePickerController.mediaTypes = @[(NSString *)kUTTypeImage];             imagePickerController.delegate = self;              self.imagePickerController = imagePickerController;              if (sourceType == UIImagePickerControllerSourceTypeCamera) {                 [self presentViewController:self.imagePickerController animated:YES completion:nil];             } else {                                     if (self.popoverVC) {                     [self.popoverVC dismissPopoverAnimated:YES];                     self.popoverVC = nil;                 }                  self.popoverVC = [[UIPopoverController alloc] initWithContentViewController:imagePickerController];                 [self.popoverVC presentPopoverFromRect:self.nameAndPicCell.picture.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];             }         }     } } 

Answer 1

I agree with Ben Lings issue detection. I would suggest a simpler solution in case when using UIActionSheet. I simply moved my code that reacts on Action Sheet selection from:

- (void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex; { // my code } 

into:

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex;  // after animation { // my code } 

This way app is guarantied that code will be executed AFTER UIActionSheet animation finishes.

Since UIAlertView has similar delegate method:

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex;  // after animation { // my code } 

I suppose that similar solution may apply.

Answer 2

I think this is because in iOS 8, alert views and action sheets are actually presented view controllers (UIAlertController). So, if you're presenting a new view controller in response to an action from the UIAlertView, it's being presented while the UIAlertController is being dismissed. I worked around this by delaying the presentation of the UIImagePickerController until the next iteration of the runloop, by doing this:

[[NSOperationQueue mainQueue] addOperationWithBlock:^{     [self openPhotoPicker:sourceType]; }]; 

However, the proper way to fix this is to use the new UIAlertController API on iOS 8 (i.e. use if ([UIAlertController class]) ... to test for it). This is just a workaround if you can't use the new API yet.