When you create an iOS 13 project in Xcode 11 use a single view app template, you will find Xcode 11 add a SceneDelegate.swift file automatically beside the AppDelegate.swift file. It defines a SceneDelegate class in the SceneDelegate.swift file, and this class takes over some UI life cycle functions which are implemented by AppDelegate class […]
Swift Xcode 11 iOS 13 Scene Delegate Life Cycle Example Read More »
In some older versions of Xcode, it uses xib files to help you to design an iOS app user interface. This article will tell you how to use xib file to design an iOS app user interface instead of the storyboard.
How To Create iOS Project With XIB File In Xcode Read More »
When I develop an iOS project in Xcode, I create a custom class RootViewController in RootViewController.swift file, this class is a subclass of UIViewController. But during the development process, when I use this custom class to create an object in another swift file ( for example SceneDelegate.swift ), I meet an error which said Use
When I follow the article How To Create A Swift App Without Storyboard to learn how to create an iOS app without using the storyboard, after I remove the Main.storyboard file and run it. I meet an error message like this Could not find a storyboard named ‘Main’ in bundle NSBundle.
When using Xcode 11 to create a new iOS project, if you still create the root view controller in AppDelegate class’s – func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool function as usual, you will find there is a compile time error which said Value of type ‘AppDelegate’ has no member ‘window’. And
How To Set Application Root View Controller Programmatically In Xcode 11 Read More »
When you develop an iOS app use swift in Xcode, the project template commonly creates a default UIViewController class defined in ViewController.swift file. This UIViewController class is used as a controller of the MVC pattern to respond to the app’s main window view’s event.
How To Present / Dismiss UIView Controller Programmatically In Swift Read More »
If you are a beginner of iOS swift programming, you may be confused by some strange swift operator, such as _, !, ?, ??. This article will tell you what dose those strange swift operator means one by one.
What Does Operator _ , ! , ? , ?? Means In Swift Read More »
When you use Mac OS Finder to browse files, you will find it can not display hidden files. This is the Mac OS default settings. But this is not user-friendly when you need to select hidden files in the Mac OS Finder to submit the hidden files to a web server. So this article will
When you view pictures on Mac OS, you may find you can only view one picture at one time. If you want to view another image picture, you should close the first image viewer, and then click and open the second image in a new image preview viewer. This is not user-friendly. This article will
How To View Multiple Pictures On Mac Continuously Read More »
When you develop an iOS app, you sometimes need to simulate memory warning notifications to test your iOS app in high memory pressure conditions. Xcode simulator just provides such a tool for you to trigger memory warning notifications. Then you can test your source code in ViewController class’s didReceiveMemoryWarning function. This article will tell you
How To Simulate Memory Warning In Xcode 10 iOS Simulator Read More »