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iOS

Posted by armanb21
armanb21
848 Points

How to stop a task running in Objective -C.

Hey guys,

I was implementing the pull to refresh in my app but I'm not sure how I can stop the instance from happening. I'm stuck in a infinite loading loop.

The code I used for the pull to refresh is here:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.
    UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
    [refreshControl addTarget:self action:@selector(refresh:) forControlEvents:UIControlEventValueChanged];
    [self.colorsTable addSubview:refreshControl];
    [self retrieveFromParse];
}

- (void)refresh:(id)sender
{

}

So how can I get the loop that keeps going on and on in a circle to stop after 6 seconds?

Thanks for your help,

Arman

1 Answer

Michael Hulet
Michael Hulet
47,912 Points
Michael Hulet
Michael Hulet
47,912 Points

The way you have it set up, the refresh: method is called every time the user attempts to pull to refresh, to handle the actual refreshing. If you want to only stop the spinning animation after 6 seconds and not do anything else, an implementation might look like this:

-(void)refresh:(id)sender{
    if([(NSObject *)sender isKindOfClass:[UIRefreshControl class]]){
        UIRefreshControl *spinner = (UIRefreshControl *)sender;
        //There's probably a better way to do this with NSTimer, but that solution would be a little complicated for the Treehouse Forum, so I'll just use C's sleep function here
        sleep(6);
        //On its own, the UIRefreshControl class doesn't know when you're done refreshing, and therefore, won't know when to stop its animation, until you tell it to
        [spinner endRefreshing];
    }
}
armanb21
armanb21
848 Points

Thanks.