Pausing an NSTimer

Question

I have a UIView with a UITableView and a UIImageView in it. The UITableView takes up the top half of the UIView

Answer 1

Keep a reference to the timer you create so you can stop it when needed. The next time you need it you can just create a new timer. It sounds like the best places for you to do this are in viewDidAppear: and viewWillDisappear:. I'm not sure why you are starting the timer on a new thread. You may have a good reasons for doing so but I have never needed to do this.

//This code assumes you have created a retained property for loadNextPhotoTimer

    - (void)viewDidAppear:(BOOL)animated {
        [super viewDidAppear:animated];
        [self startTimer];
    }

    - (void)viewWillDisappear:(BOOL)animated {
        [super viewWillDisappear:animated];
        [self stopTimer];
    }

    - (void)startTimer {
        NSTimer *timer = [[NSTimer alloc] initWithFireDate:[NSDate dateWithTimeIntervalSinceNow:3.0] interval:3.0 target:self selector:@selector(loadNextPhoto) userInfo:nil repeats:YES];
        [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
        self.loadNextPhotoTimer = timer;
        [timer release];
    }

    - (void)stopTimer {
        [self.loadNextPhotoTimer invalidate];
        self.loadNextPhotoTimer = nil;
    }