How to dispatch code blocks to the same thread in iOS?

Question

Main aspect of the question: It\'s about iOS. Can I somehow dispatch code blocks in a way, that they will all (a) run in background and (b) on the same thread?

Answer 1

If you want to perform a selector in Main Thread, you can use

- (void)performSelectorOnMainThread:(SEL)aSelector withObject:(id)arg waitUntilDone:(BOOL)wait

and if you want to it to perform in background thread

- (void)performSelectorInBackground:(SEL)aSelector withObject:(id)object

and if you want to perform in any other thread use GCD(Grand Central Dispatch)

double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        //code to be executed on the main queue after delay
    });