GCD Example

test.h

{

dispatch_queue_t backgroundQueue;

}

test.m

- (void)viewDidLoad

{

    [super viewDidLoad];

   //com.unique.uniqueidentifier.youtube is any unique name

    backgroundQueue = dispatch_queue_create("com.unique.uniqueidentifier.youtube", NULL);

    

}

-(void)anyFunction

{

      dispatch_async(backgroundQueue, ^(void){

             [self sendRequestForData];

       });

}

-(void)sendRequestForData

{

    NSString *post = @"";

    NSData *postData = [post dataUsingEncoding:NSISOLatin1StringEncoding allowLossyConversion:NO];

    NSMutableURLRequest *urlRequest = [[[NSMutableURLRequest alloc] init] autorelease];

    [urlRequest setURL:[NSURL URLWithString:<any url string for fetching data from server>]];

    [urlRequest setHTTPMethod:@"GET"]; 

    [urlRequest setHTTPBody:postData];

    NSData *urlData; 

    NSURLResponse *response; 

    NSError *error;

    

    

    urlData = [NSURLConnection sendSynchronousRequest:urlRequest returningResponse:&response error:&error]; 

    if(!urlData) {

        NSLog(@"No connection!");

    }else {

       

    }

    

   //Back To main thread

    

    dispatch_async(dispatch_get_main_queue(), ^(void){

        //Reload the data

        [mtableview reloadData];

        

    });

}