Question

I have Navigation controller as intial view which goes into view controller

now i have table view after this view

Nav controller > UI View Controller > Table view

Issue occurs here

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{   
    UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
    MasterViewController2 *controller = (MasterViewController2 *)navigationController.topViewController;
    controller.managedObjectContext = self.managedObjectContext;
    return YES;
}

app builds and fails with this message

'NSInvalidArgumentException', reason: '-[ViewController setManagedObjectContext:]: unrecognized selector sent to instance 0x8e22df0'

any idea why its failing and crashing app even though there is no build errors or warnings?

Answer 1

You need to set the class of your view controller in the storyboard to MasterViewController2. The exception is showing you that the object is of type ViewController with the message '-[ViewController setManagedObjectContext:]:. This is in the identity inspector (View → Utilities → Show Identity Inspector with your view controller selected).