The error occurs because you are trying to present SecondController from FirstController after you have dismissed FirstController. This doesn’t work: self.dismiss(animated: true, completion: { let vc = SecondController() // ‘self’ refers to FirstController, but you have just dismissed // FirstController! It’s no longer in the view hierarchy! self.present(vc, animated: true, completion: nil) }) This problem … Read more
If you’re using a storyboard, you probably shouldn’t be using alloc and init to create a new view controller. Instead, look at your storyboard and find the segue that you want to perform; it should have a unique identifier (and if not, you can set one in the right sidebar). Once you’ve found the identifier … Read more
You are trying to present a view controller from the rootViewController. In your case I think the rootViewController is not the current ViewController. Either you presented or pushed a new UIViewController on top of it. You should present a view controller from the top most view controller itself. You need to change: UIViewController *vc = … Read more
To create a view controller: UIViewController * vc = [[UIViewController alloc] init]; To call a view controller (must be called from within another viewcontroller): [self presentViewController:vc animated:YES completion:nil]; For one, use nil rather than null. Loading a view controller from the storyboard: NSString * storyboardName = @”MainStoryboard”; UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil]; UIViewController … Read more
Try this: let vc = ViewController() //change this to your class name self.presentViewController(vc, animated: true, completion: nil) With Swift3: self.present(vc, animated: true, completion: nil)
This line: [self dismissViewControllerAnimated:YES completion:nil]; isn’t sending a message to itself, it’s actually sending a message to its presenting VC, asking it to do the dismissing. When you present a VC, you create a relationship between the presenting VC and the presented one. So you should not destroy the presenting VC while it is presenting … Read more
At this point in your code the view controller’s view has only been created but not added to any view hierarchy. If you want to present from that view controller as soon as possible you should do it in viewDidAppear to be safest.
You may need to put the NSPhotoLibraryUsageDescription in your plist. Like <key>NSPhotoLibraryUsageDescription</key> <string>$(PRODUCT_NAME) uses photos</string> Check all the usage descriptions here.