Instantiating UITableViewController in AppDelegate to work with Storyboard iOS

Question

Need help with a "Application windows are expected to have a root view controller at the end of application launch" warning in my console when running my app. It's a core data test I am working on. I am not getting the NSLog statements I am using for testing, only the previous message.

I created a new project from an Empty Application. My app delegate didFinish method code was generated to look like this:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary     *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

I added a storyboard and set it as the Main Interface. Then added a UITableView to the storyboard. Created a UITableViewController by adding a file and set it as the UITableView's class in the identity inspector.

It seems to get rid of the warning I should set the rootViewController. How do I set my UITableViewController as the rootViewController if I did not instantiate it in the appDelegate.m file? Alternately, If I do instantiate it in the appDelegate.m like so

UITableViewController *tableViewController = [[UITableViewController alloc]init];
self.window.rootViewController = tableViewController;

how do I associate tableViewController with corresponding .h and .m files?

Using Xcode 5.0.1, deployment target 7.0

Answer 1

When you add a storyboard to your empty application, and set the property "Main Storyboard file base name" in your Info.plist as the name of your storyboard, then the application instantiates your "window" object and assigns an instance of your storyboard's "initialViewController" as the "rootViewController" property of your window object. So you don't see the warning :

"Application windows are expected to have a root view controller at the end of application launch" when you do :

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary     *)launchOptions {     
    return YES;
}

This works fine.

However, in the code :

-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary     *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]
    //Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

If you were using storyboards, you have overridden default behaviour by creating a new window object, which no longer has the rootViewController provided by storyboard. In this case, you have to explicitly add a root view controller to your window object.

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

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"YourStoryboard" bundle:[NSBundle mainBundle]];
    YourTableViewController* vc = (YourTableViewController*)[storyboard instantiateInitialViewController];

    _window.rootViewController = vc;

    [self.window makeKeyAndVisible];
    return YES;
}

Hope this helps !!

Answer 2

In StoryBoard set the desired controller as initialViewController.

In AppDelegate.m

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    youRootViewControllerObject = [storyboard instantiateInitialViewController];

This way you can access YouRootViewController class.

Answer 3

I did a lot of research and finally found out the right way to do this

in appDelegate.m instead of

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary     *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

The code should simply be

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

    return YES;
}

See Sitepoint's helpful page for more detailed information http://www.sitepoint.com/ios-application-development-storyboards/