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... @implementation RootViewController ... @synthesize cLoadingView; ... - (IBAction)doSomethingComplexAndTimeConsuming { // this is how we start spinning [NSThread detachNewThreadSelector: @selector(spinBegin) toTarget:self withObject:nil]; ... // TODO: something very complex and time consuming // you can also add extra wait for the test (just uncomment line below) //[NSThread sleepForTimeInterval:3] ... // stop waiting... [NSThread detachNewThreadSelector: @selector(spinEnd) toTarget:self withObject:nil]; ... // TODO: continue with our application } ... - (void)initSpinner { cLoadingView = [[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge] autorelease]; // we put our spinning "thing" right in the center of the current view CGPoint newCenter = (CGPoint) [self.view center]; cLoadingView.center = newCenter; [self.view addSubview:cLoadingView]; } ... - (void)spinBegin { [cLoadingView startAnimating]; } ... - (void)spinEnd { [cLoadingView stopAnimating]; } ... - (void)viewDidLoad { [self initSpinner]; [super viewDidLoad]; } ... @end ...

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