UIImagePickerController camera freezes when flip and cancel a few times - objective-c

Question

Hello I'm working in an app with camera.
I can open and use the camera correctly. But I find a bug:
When I open the camera, flips camera, again flips camera and press cancel. Do it a few times ( 3 - 5 ) . Open again the camera and I have a black freeze screen for a few seconds and if you take a picture see the image but the screen continue in black. After a few seconds the camera appears again and you can continue with the normal behavior. But I cant find a solution to this.
I searched a lot in internet and find some answers but nothing solve my problem.
Here a similar problem but the solution didnt work for me:
Stackoverflow - UIImagePickerController Freezes when camera flips
Stackoverflow - UIImagePicker freezes
Stackoverflow - iOS 7 UIImagePicker preview black screen
Stackoverflow - iDevice camera shows black instead of preview
Also I use DejalBezelActivityView to create a spinner area with a label DejalBezelActivityView
Any idea?
I have my .h declaration:
#property (nonatomic, strong) UIImagePickerController* picker;
- (void) takePhoto: (id)vc;
- (void) selectPhoto: (id)vc;
And my .mm code:
#synthesize picker = _picker;
- (id) init{
self = [super init];
if (self){
self.picker = [[UIImagePickerController alloc] init];
}
return self;
}
- (void)takePhoto:(id)vc{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
[VC_Camera showAlert];
return;
}
[self init];
self.picker.delegate = self;
self.picker.allowsEditing = YES;
self.picker.sourceType = UIImagePickerControllerSourceTypeCamera;
self.picker.cameraDevice = UIImagePickerControllerCameraDeviceRear;
[[VC_Camera getMainWindow] presentViewController:self.picker animated:YES completion:NULL];
}
- (void)selectPhoto:(id)vc{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]){
[VC_Camera showAlert];
return;
}
[self init];
self.picker.delegate = self;
self.picker.allowsEditing = YES;
self.picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[[VC_Camera getMainWindow] presentViewController:self.picker animated:YES completion:NULL];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
self.picker = picker;
DejalActivityView * _activityView = [DejalBezelActivityView activityViewForView:[[UIApplication sharedApplication] keyWindow] withLabel:#"Loading"];
[self performSelector:#selector(cancelAfterDelay:) withObject:#{#"DejalAV":_activityView} afterDelay:1.0];
}
- (void) cancelAfterDelay:(NSDictionary*) dict
{
DejalActivityView* _activityView = [dict objectForKey:#"DejalAV"];
[DejalBezelActivityView removeViewAnimated:YES];
[self.picker dismissViewControllerAnimated:YES completion:nil];
}
Thanks :D
[UPDATE]
I try to use the UIImagePickerController as a singleton:
-(UIImagePickerController *) imagePicker{
if(!_imagePicker){
_imagePicker = [[UIImagePickerController alloc] init];
_imagePicker.delegate = self;
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]){
_imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
}
else{
_imagePicker.sourceType =UIImagePickerControllerSourceTypePhotoLibrary;
}
}
return _imagePicker;
}
And the problem persist.

Answer 1

This is a very late response, but for those still wrestling with this issue: I've noticed this seems to happen when something is either backing up the main thread, or affecting the graphics context on a separate thread. Those might be places to start looking.