title: why [response expectedContentLength] always return -1
body: <pre><code>-(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse    *)response {
      [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
      if([recievedData length]) [ recievedData setLength:0 ];
  
      download_size =[response expectedContentLength];
  }
  </code></pre>
  
  <p>I have this code. download_size is NSInteger.
  expectedContentLenght always return: -1.
  Maybe someone know why? I tried use long, but effect was the same.</p>
  
  <p>Thanks for help.</p>