IOS/Objective-C: Syntax error with NSURL URLWithString

Question

I am trying to implement code from SO answer with a slight modification but having problems:

Here is the original code:

     dispatch_async(kBgQueue, ^{
            NSData *imgData = [NSData dataWithContentsOfURL:[NSURL 
URLWithString:[NSString stringWithFormat:@"http://myurl.com/%@.jpg",
[[myJson objectAtIndex:indexPath.row] objectForKey:@"movieId"]]]];

Here is my code:

  NSString *picname = item.pic;
     NSString *picURL = [NSString stringWithFormat:@"http://www.~com/itempics/%@",item.pic];
     NSURL *urlPicUrl = [NSURL URLWithString:picURL];
    dispatch_async(kBgQueue, ^{ 
                NSData *imgData = [NSData dataWithContentsOfURL:
[NSURL URLWithString:picURL]]; //THROWS ERROR

My code is throwing error

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSPlaceholderString initWithString:]: nil argument'

Would appreciate it if anyone can spot what is causing this error:

Answer 1

I guess item.pic is null. And picname is never used in your code.

Did you miss something to paste in your code?