Why does code in iOS only work in the didFinishLaunchingWithOptions method?

Question

Objective-C

I'm using the StartApp SDK in an iOS app to display ads. Downloaded the official sample iOS app here https://github.com/StartApp-SDK/StartApp-InApp-iOS... . In the example, in the STAAppDelegate class, in the didFinishLaunchingWithOptions method, there is code for displaying ads:

STAStartAppSDK* sdk = [STAStartAppSDK sharedInstance];
[sdk SDKInitialize:@"103738633" andAppID:@"203184123"];
[sdk showSplashAd];

Everything works, but if this code is inserted in another place, for example, a button click handler, then the ad is not displayed.
Question: what are the special properties of the didFinishLaunchingWithOptions method that the above code only works in it? And what can be done to make this code work in the button click handler?

Answer 1

Because the iOS application has all the delegates here! And the late finish is the beginning of the life cycle of the application, it is launched by the main!

Answer 2

Try
preg_match("#{$d['keywords']}#i", $text)