Question

Is there a way in iOS4 to call a method after a delay using something else other than NSThread or blocking the UI using sleep()?

Answer 1

    double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        // code to be executed on main thread.If you want to run in another thread, create other queue
    });