Question

I am having a strange problem.I am having a button , and on pressing the button I am doing

the following

- (IBAction)btnPressed:(id)sender {

    [ _spinner startAnimating];//where _spinner is a ActivityIndicator

    [self showResult];

}

-(void) showResult{

    sleep(10);

    resultText.text=@"Hi..Sorry.It has been a long wait";

}

But the spinner never starts animating , even though the showResult method gets called

properly. I feel this very strange . When I put [_spinner startAnimating] in the viewDidLoad

it works perfect. Any help is greatly appreciated.

Answer 1

sleep method get called on the main thread causing UI to hang, that’s why you aren’t able to see the activity indicator

one way to do this:

- (IBAction)actionbuton:(id)sender {

    [_activity startAnimating];

    [self performSelectorInBackground:@selector(backgroundProcess) withObject:nil];
}

- (void) backgroundProcess{

    sleep(4);
    [self performSelectorOnMainThread:@selector(processingDone) withObject:nil waitUntilDone:NO];
}

- (void) processingDone{

    [_activity stopAnimating];
}