Question

I want to execute a code snippet when program start-up, so what is the start-up function of iOS program?

For Android program, the start-up function is onCreate as below

public class HelloWorld extends Activity {
   public void onCreate(Bundle savedInstanceState) {
       ...

How about iOS program?

Thanks

Answer 1

In iOS you use the UIApplicationDelegate protocol in order to be informed of application lifecycle events (startup, suspend, shutdown, etc.):

@interface MyAppDelegate : NSObject <UIApplicationDelegate> {
}
@end

@implementation MyAppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //start-up code here

    return YES;
}
@end

Assuming that you are using XCode for your iOS project, it will have created a default UIApplicationDelegate class for you. All you need to do is find it and edit the application:didFinishLaunchingWithOptions: method to your liking.