iOS 应用程序 xcode 构建错误

Question

I am new to iOS development and struggling with few build errors. I looked up the web on how to fix these errors but could not get a hint. Using Xcode 9.4 with built in Swift.

1. 'LaunchOptionsKey' is not a member type of 'UIApplication'
2. Instance member 'state' cannot be used on type 'UIControl'
3. Instance member 'state' cannot be used on type 'UIControl'
4. Type 'UIControl' has no member 'State'

Link is below as I was not allowed to include the screenshot in this post.

Xcode build errors

Answer 1

It should be like this :

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    return true
}

Answer 2

Neither the original question nor the accepted answer note that the code with the error is generated code when a project is created and as such generally shouldn't need to be changed.

The problem is because of the version of Xcode. UIApplicationLaunchOptionsKey has been renamed to UIApplication.LaunchOptionsKey in the newer version of Xcode (10.2). I came across this when I tried to open my project in an older version of Xcode. This sucks because I now can't work on my project on my older computer that can't be updated to the latest version.

Answer 3

I am running Xcode 9.3 and Android Studio 3.5.1.

All I did was remove the "." on the definition:

UIApplication.LaunchOptionsKey: Any

To:

UIApplicationLaunchOptionsKey: Any

without the period. Works like a charm! Enjoy.