How to set rootViewController?

Question

I am trying to learn this book but all the examples are without storyBoard, and when I tried to build the application I caught this error:

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Application windows are expected to have a root view controller at the end of application launch'

I tried to fix it with this:

ViewController *myView = [[ViewController alloc] init];
[self.window addSubview:myView];
self.window.rootViewController = myView;

but then I received another error:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[HypnoView _preferredInterfaceOrientationGivenCurrentOrientation:]: unrecognized selector sent to instance 0x78f68730'

Can someone explain to me why is it happening to me?

Answer 1

Firstly you cannot add an

UIViewController 

as a subview

The method

addSubview:(UIView *)

expects a UIview and you are adding a UIViewController.

Secondly adding subview was used in iOS 4 and earlier, Now you add a view controller as rootviewcontroller.

So simply add,

self.window.rootViewController = myView

In case you wish to use addSubview, you need to do this

[self.window addSubView:myView.view]

Answer 2

Goto AppDelegate.m

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
    self.window.rootViewController = self.viewController;
    return YES;
}

Answer 3

It's done this way. Go to AppDelegate.m and go to - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

ViewController *myView = [[ViewController alloc] init];
self.window.rootViewController = myView;
[self.window makeKeyAndVisible];

If you want to add an UIView as a subview. Then do the following:

UIView *view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window makeKeyAndVisible];
[self.window addSubview:view];

Answer 4

Objective-c

@interface AppDelegate () 
    @property (nonatomic, strong) ViewController *viewController;
@end


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [self setViewController:[[ViewController alloc] init]];

    [self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]];
    [[self window] setBackgroundColor:[UIColor redColor];
    [[self window] setRootViewController:[self viewController]];
    [[self window] makeKeyAndVisible];

    return YES;
}

Swift

var window: UIWindow?
let viewController = ViewController();

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    self.window!.backgroundColor = UIColor.redColor()
    self.window!.rootViewController = playerController
    self.window!.makeKeyAndVisible()

    return true
}

Answer 5

Try this code

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
_window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];

ViewController *controller = [[ViewController alloc]initWithNibName:@"View" bundle:nil];
UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:controller];
[self.window setRootViewController:nav];
[self.window makeKeyAndVisible];
return YES;
}

Answer 6

You need to set:-

in AppDelegate.m file: _applicationDidFinishLaunchingWithOptions_

UIView *myView;
    self.window.rootViewController = myView

        myView= self.viewController;
        [self.window makeKeyAndVisible];