You can access the delegate like this: MainClass *appDelegate = (MainClass *)[[UIApplication sharedApplication] delegate]; Replace MainClass with the name of your application class. Then, provided you have a property for the other view controller, you can call something like: [appDelegate.viewController someMethod];
Starting in iOS7, the view controllers use full-screen layout by default. At the same time, you have more control over how it lays out its views, and that’s done with those properties: edgesForExtendedLayout Basically, with this property you set which sides of your view can be extended to cover the whole screen. Imagine that you … Read more
It’s possible in iOS 6 and later: You have to implement the method – (BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender In your view controller. You do your validation there, and if it’s OK then return YES; if it’s not then return NO; and the prepareForSegue is not called. Note that this method doesn’t get called automatically when triggering … Read more
How to without a dummy initial view controller Ensure all initial view controllers have a Storyboard ID. In the storyboard, uncheck the “Is initial View Controller” attribute from the first view controller. If you run your app at this point you’ll read: Failed to instantiate the default view controller for UIMainStoryboardFile ‘MainStoryboard’ – perhaps the … Read more
I think you need a combination of the accepted answer and @fishstix’s + (UIViewController*) topMostController { UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController; while (topController.presentedViewController) { topController = topController.presentedViewController; } return topController; } Swift 3.0+ func topMostController() -> UIViewController? { guard let window = UIApplication.shared.keyWindow, let rootViewController = window.rootViewController else { return nil } var topController = … Read more
All these commands are called automatically at the appropriate times by iOS when you load/present/hide the view controller. It’s important to note that these methods are attached to UIViewController and not to UIViews themselves. You won’t get any of these features just using a UIView. There’s great documentation on Apple’s site here. Putting in simply … Read more
This answer was last revised for Swift 5.4 and iOS 14.5 SDK. It’s all a matter of new syntax and slightly revised APIs. The underlying functionality of UIKit hasn’t changed. This is true for a vast majority of iOS SDK frameworks. let storyboard = UIStoryboard(name: “myStoryboardName”, bundle: nil) let vc = storyboard.instantiateViewController(withIdentifier: “myVCID”) self.present(vc, animated: … Read more
The view’s window property is non-nil if a view is currently visible, so check the main view in the view controller: Invoking the view method causes the view to load (if it is not loaded) which is unnecessary and may be undesirable. It would be better to check first to see if it is already … Read more
This question seems to be very popular here on Stack Overflow so I thought I would try and give a better answer to help out people starting in the world of iOS like me. Passing Data Forward Passing data forward to a view controller from another view controller. You would use this method if you wanted … Read more