iOS Tutorial

How To Connect Storyboard UI Component To ViewController Class Code

When we develop iOS app use Xcode, we design the app GUI ( graphical user interface ) in Main.storyboard file. And the swift source code is edited in ViewController.swift file. But how to use swift source code in ViewController.swift file to modify storyboard UI component’s attributes or process UI component’s action event? This article will […]

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How To Fix Error ‘Value Of Optional Type Must Be Unwrapped To A Value Of Type’ In Swift

There are three kinds of variable declaration in swift programming. You can declare a swift variable as a variable (var name: String = “jerry”) that value can be changed in code, a constant ( let x:Int = Int(10) ) that value can not be changed, and an optional variable ( var x:Int? ) that value

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