NSTimer is not calling in background method

Question

I got stuck in a problem. I'm trying to run a timer in a method which itself is in background resulting my timer is not initiating. I got to know some where that timer can't be initialized in background so is there any way to do this?

Answer 1

You can perform the operation on main thread.

[self performSelectorOnMainThread:@selector(initTimer) withObject:nil waitUntilDone:NO];

and then

- (void)initTimer {
// Init your timer here.
}

Answer 2

You can try Background Fetch in ios7 to run code on background

Answer 3

Try this :

// provide value as required. Time here is 3 sec
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 3.0 * NSEC_PER_SEC); 

dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    // do your task
});

Answer 4

As pointed out by @Bryan Chen, you can schedule a method to be run on the current thread using the following code:

dispatch_time_t when = dispatch_time(DISPATCH_TIME_NOW, 0.3 * NSEC_PER_SEC);
dispatch_after(when, dispatch_get_current_queue(), ^(void) {
    [self myTimedMethod];
});

You cannot use NSTimer in a background thread unless you are maintaining a run loop on that thread.