EXC_BAD_ACCESS / KERN_INVALID_ADDRESS associated with orientation changes

Question

I have a strange problem. I received an error message stating that the application crashed due to a change in orientation. The problem is that I did not subscribe to any indicative events in the application code at all. The only thing related to changing orientation changes:

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return IS_IPAD ? YES : interfaceOrientation == UIInterfaceOrientationPortrait; } 

... on all view controllers, so that it changes orientation on the iPad, but not the iPhone. And the error occurred on the iPhone.

IS_IPAD comes from this:

 #ifdef UI_USER_INTERFACE_IDIOM #define IS_IPAD (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) #else #define IS_IPAD (false) #endif 

It seems that -[UIWindow _updateInterfaceOrientationFromDeviceOrientation:] calls some object that no longer exists. What can be an object if I am not registered for any orientation related notifications?

Answer 1

The stack trace shows that the NSNotificationCenter trying to notify the object, apparently, of a change in orientation. You may have registered such an object, but it is no longer there, and it was not unregistered until release. This could lead to such an error.

Answer 2

If you are running iOS 6 or later, you also need to implement the following methods:

 // Support iOS 6 - (BOOL)shouldAutorotate { return IS_IPAD ? YES : NO; } // Support iOS 6 - (NSUInteger)supportedInterfaceOrientations { return IS_IPAD ? UIInterfaceOrientationMaskAll : UIInterfaceOrientationMaskPortrait; } 

Check to see if this issue resolves the issue.

Answer 3

The method used is out of date. The shouldAutorotate method is a new way to support autorotation. I tried this and it worked the way you want:

 -(BOOL) shouldAutorotate{ return IS_IPAD ? YES : [self preferredInterfaceOrientationForPresentation] == UIInterfaceOrientationMaskPortrait; } 

Hope this helps :)