Objective-C: unrecognized selector sent to instance 0xba3e750

0
votes

I have written this code and when I run the program it throws exception: unrecognized selector sent to instance 0xba3e750

 storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    navigationController = [storyboard instantiateViewControllerWithIdentifier:@"SecondViewID"];
    selected = navigationController.viewControllers[0];

when I put this line in comment

//selected = navigationController.viewControllers[0];

like that , the program doesn't throw exception. this is whole exception

2014-06-12 20:59:44.749 passing image[2194:a0b] -[SecondViewController viewControllers]: unrecognized selector sent to instance 0xba3e750 2014-06-12 20:59:44.753 passing image[2194:a0b] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[SecondViewController viewControllers]: unrecognized selector sent to instance 0xba3e750' * First throw call stack: ( 0 CoreFoundation 0x017445e4 exceptionPreprocess + 180 1 libobjc.A.dylib 0x014c78b6 objc_exception_throw + 44 2 CoreFoundation 0x017e1903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275 3 CoreFoundation 0x0173490b ___forwarding_ + 1019 4 CoreFoundation 0x017344ee _CF_forwarding_prep_0 + 14 5 passing image 0x000056a2 -[ViewController viewDidLoad] + 466 6 UIKit 0x00349318 -[UIViewController loadViewIfRequired] + 696 7 UIKit 0x003495b4 -[UIViewController view] + 35 8 UIKit 0x002719fd -[UIWindow addRootViewControllerViewIfPossible] + 66 9 UIKit 0x00271d97 -[UIWindow _setHidden:forced:] + 312 10 UIKit 0x0027202d -[UIWindow _orderFrontWithoutMakingKey] + 49 11 UIKit 0x0027c89a -[UIWindow makeKeyAndVisible] + 65 12 UIKit 0x0022fcd0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1851 13 UIKit 0x002343a8 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824 14 UIKit 0x0024887c -[UIApplication handleEvent:withNewEvent:] + 3447 15 UIKit 0x00248de9 -[UIApplication sendEvent:] + 85 16 UIKit 0x00236025 _UIApplicationHandleEvent + 736 17 GraphicsServices 0x037932f6 _PurpleEventCallback + 776 18 GraphicsServices 0x03792e01 PurpleEventCallback + 46 19 CoreFoundation 0x016bfd65 CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION + 53 20 CoreFoundation 0x016bfa9b __CFRunLoopDoSource1 + 523 21 CoreFoundation 0x016ea77c __CFRunLoopRun + 2156 22 CoreFoundation 0x016e9ac3 CFRunLoopRunSpecific + 467 23 CoreFoundation 0x016e98db CFRunLoopRunInMode + 123 24 UIKit 0x00233add -[UIApplication _run] + 840 25 UIKit 0x00235d3b UIApplicationMain + 1225 26 passing image 0x0000750d main + 141 27 libdyld.dylib 0x01e78725 start + 0 28 ??? 0x00000001 0x0 + 1 ) libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

1
iosexception
can you please add the whole error message from console. – lootsch
it seems, that your ViewController "SecondViewController" isn't a UINavigationController. – lootsch
property UIStoryboard *storyboard; property UINavigationController *navigationController; property SecondViewController *selected; – Vahe Muradyan
@Caleb sorry, i meant UINavigationController of course. My bad. – lootsch

1 Answers

1
votes

instantiateViewControllerWithIdentifier: returns a UIViewController, but you're storing it in a UINavigationController when you shouldn't. When you try to access a UINavigationController property (viewControllers), it crashed because UIViewController doesn't have a property named viewControllers.

Try storing the return of the method instantiateViewControllerWithIdentifier: in a UIViewController instead of a UINavigationController :

UIViewController * viewController = [storyboard instantiateViewControllerWithIdentifier:@"SecondViewID"];
selected = viewController.navigationController.viewControllers[0];