“Application tried to present modally an active controller”?

by

Assume you have three view controllers instantiated like so:

UIViewController* vc1 = [[UIViewController alloc] init];
UIViewController* vc2 = [[UIViewController alloc] init];
UIViewController* vc3 = [[UIViewController alloc] init];

You have added them to a tab bar like this:

UITabBarController* tabBarController = [[UITabBarController alloc] init];
[tabBarController setViewControllers:[NSArray arrayWithObjects:vc1, vc2, vc3, nil]];

Now you are trying to do something like this:

[tabBarController presentModalViewController:vc3];

This will give you an error because that Tab Bar Controller has a death grip on the view controller that you gave it. You can either not add it to the array of view controllers on the tab bar, or you can not present it modally.

Apple expects you to treat their UI elements in a certain way. This is probably buried in the Human Interface Guidelines somewhere as a “don’t do this because we aren’t expecting you to ever want to do this”.

More Related Contents:

  1. UIImage resizing not working properly
  2. Container View Controller Examples [closed]
  3. iOS Background downloads when the app is not active
  4. Use regular expression to find/replace substring in NSString
  5. NSURLConnection sendAsynchronousRequest:queue:completionHandler: making multiple requests in a row?
  6. Application windows are expected to have a root view controller at the end of application launch warning
  7. Objective-C ARC: strong vs retain and weak vs assign
  8. Why are Objective-C delegates usually given the property assign instead of retain?
  9. How do I implement an Objective-C singleton that is compatible with ARC?
  10. How to write iOS app purely in C
  11. Synthesized property and variable with underscore prefix: what does this mean? [duplicate]
  12. Any way to bold part of a NSString?
  13. presentViewController: crash on iOS
  14. NSInvalidUnarchiveOperationException: Could not instantiate class named NSLayoutConstraint
  15. convert UIImage to NSData
  16. Should I refer to self.property in the init method with ARC?
  17. Implementing a method taking a block to use as callback
  18. iOS start Background Thread
  19. In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
  20. Appending to the end of a file with NSMutableString
  21. iOS 5: How to convert an Emoji to a unicode character?
  22. Converting iPhone app to a Universal app in Xcode 4
  23. How do I download and save a file locally on iOS using objective C? [duplicate]
  24. iOS Screenshot part of the screen
  25. How do I support the taller iPhone 5 screen size?
  26. PBKDF2 using CommonCrypto on iOS
  27. Is it possible to detect that your iOS app is running on an iPad mini at runtime?
  28. How to enable the new Objective-C object literals on iOS?
  29. Detecting if UIView is intersecting other UIViews
  30. IBOutletCollection set ordering in Interface Builder

Leave a Comment