UIActivityIndicatorView Not Stopping When I want - ios

Question

I need to show a UIActivityIndicatorView when calling of a WebService is take place. However, the activity indicator keeps on showing even after i have received response from web service. It stops only after 5-6 seconds after i receive response. How to make it stop at the moment i am receiving a response?
Here's my code: (configuring UIActivityIndicatorView) and calling my webservice:
loadView = [[UIView alloc] initWithFrame:self.view.bounds];
loadView.backgroundColor = [UIColor colorWithWhite:0.0 alpha:0.5];
//UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc] init];
//[second.loadingView addSubview:activityView];
//activityView.center = second.loadingView.center;
//[second.view addSubview:second.loadingView];
activity = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[loadView addSubview:activity];
activity.center = loadView.center;
[self.view addSubview:loadView];
[self.view bringSubviewToFront:loadView];
activity.hidesWhenStopped = YES;
[activity setHidden:NO];
//[activity performSelectorInBackground: #selector(startAnimating) withObject: nil];
[activity startAnimating];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
[self callRegisterWebService:self.userFname lastName:self.userLName email:self.userEmail];
});
I am stopping the animation in the finally block.
-(void)callRegisterWebService:(NSString *)fname lastName:(NSString *)lName email:(NSString *)email
{
NSString *serviceURL = [NSString stringWithFormat:#"https:abcdefghi..."];
#try {
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:serviceURL]];
NSURLResponse *serviceResponse = nil;
NSError *err = nil;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&serviceResponse error:&err];
NSMutableDictionary *parsedData = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:&err];
if(!parsedData)
{
NSLog(#"data not parsed");
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"ERROR" message:#"Problem in Network. Please Try Again!" delegate:self cancelButtonTitle:#"OK" otherButtonTitles: nil];
[alert show];
}
else
{
NSString *status = [parsedData objectForKey:#"Status"];
if([status isEqualToString:#"Success"])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NULL message:#"Authentication Token Has Been Sent To Your Email-ID!" delegate:self cancelButtonTitle:#"OK" otherButtonTitles: nil];
[alert show];
NSString *uniqueNumber = [parsedData objectForKey:#"UniqueNum"];
[self saveEmailAndUniqueNumberToDatabase:fname lastName:lName Email:email Number:uniqueNumber];
}
else if([status isEqualToString:#"Failed"])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Not An Authorized User" message:#"Please Contact Admin To Get Access" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil];
[alert show];
}
else
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"ERROR" message:#"Problem in Network. Please Try Again!" delegate:self cancelButtonTitle:#"OK" otherButtonTitles: nil];
[alert show];
}
}
}
#catch (NSException *exception)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NULL message:#"Problem In Network Connection. Please Try Again!" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
}
#finally {
[activity stopAnimating];
[loadView setHidden:YES];
}
}

Answer 1

There are 2 issues in your code:
You are manipulating UI component from a background thread, never do that. Use main thread for UI manipulations
You wrote the activity indicator functionality in the finally clause, so it'll be hidden only after executing all the statements in try clause
Change your method like:
- (void) hideActivity
{
dispatch_async(dispatch_get_main_queue(), ^{
[activity stopAnimating];
[loadView setHidden:YES];
activity = nil;
loadView = nil;
});
}
-(void)callRegisterWebService:(NSString *)fname lastName:(NSString *)lName email:(NSString *)email
{
NSString *serviceURL = [NSString stringWithFormat:#"https:abcdefghi..."];
NSString *message = #"";
NSString *title = #"";
#try
{
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:serviceURL]];
NSURLResponse *serviceResponse = nil;
NSError *err = nil;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&serviceResponse error:&err];
NSMutableDictionary *parsedData = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:&err];
[self hideActivity];
if(!parsedData)
{
message = #"Problem in Network. Please Try Again!";
title = #"ERROR";
}
else
{
NSString *status = [parsedData objectForKey:#"Status"];
if([status isEqualToString:#"Success"])
{
message = #"Authentication Token Has Been Sent To Your Email-ID!";
title = nil;
NSString *uniqueNumber = [parsedData objectForKey:#"UniqueNum"];
[self saveEmailAndUniqueNumberToDatabase:fname lastName:lName Email:email Number:uniqueNumber];
}
else if([status isEqualToString:#"Failed"])
{
message = #"Please Contact Admin To Get Access";
title = #"Not An Authorized User";
}
else
{
message = #"Problem in Network. Please Try Again!";
title = #"ERROR";
}
}
}
#catch (NSException *exception)
{
if (activity != nil && loadView != nil)
{
[self hideActivity];
}
message = #"Problem In Network Connection. Please Try Again!";
title = nil;
}
#finally
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:message delegate:self cancelButtonTitle:#"OK" otherButtonTitles: nil];
[alert show];
}
}