subclassing UIWindow while using storyboards subclassing UIWindow while using storyboards ios ios

subclassing UIWindow while using storyboards

UIWindow in a Storyboard project can be subclassed as explained in Apple's UIApplicationDelegate reference:

When a storyboard is being used, the application must present the storyboard by adding it to a window and putting that window on-screen. The application queries this property for the window. The retained reference to the window by this property is necessary to keep the window from being released. If the value of the property is nil (the default), the application creates a generic instance of UIWindow and assign it to this property for the delegate to reference. You may implement the getter method of this protocol to provide the application with a different window.

In other words in your AppDelegate implementation simply add the following getter


- (MyCustomWindow *)window{        static MyCustomWindow *customWindow = nil;    if (!customWindow) customWindow = [[MyCustomWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    return customWindow;}


var customWindow: MyCustomWindow?    var window: UIWindow? {    get {        customWindow = customWindow ?? MyCustomWindow(frame: UIScreen.mainScreen().bounds)        return customWindow    }    set { }}

Its not so hard you're going to first subclass UIWindow

class WinCustom : UIWindow{ ....}

then in AppDelegate:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {    self.window = WinCustom(frame: UIScreen.main.bounds)    self.window?.rootViewController = UIStoryboard(name: "Main", bundle: nil).instantiateInitialViewController()    return true}

In my own apps, I've seen "window" property declared in AppDelegate.h when creating a new app from the Xcode templates.

You can modify that property to change from "UIWindow" to "MyWindow" at that point.

Or, a less elegant solution, you can simply cast window's return to a "MyWindow" object type when accessing it.