When I use NSURLConnection to get file, the expectedContentLength alway return -1.
After look lots of similary problem it looks like never send the Content-Length.
Checking the code below, you will get a surprise: replace _ssqUrl to your variable.
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:_ssqUrl]];
[request setCachePolicy:NSURLRequestUseProtocolCachePolicy];
[request setTimeoutInterval:5.0];
[request setHTTPMethod:@"GET"];
[request setValue:@"" forHTTPHeaderField:@"Accept-Encoding"];
[request setValue:@"application/x-www-form-urlencoded"forHTTPHeaderField:@"Content-Type"];
Most importent is :
[request setValue:@"" forHTTPHeaderField:@"Accept-Encoding"];
The response will be compress with "Gzip". And if the response is encode with Gzip it's impossible to know the length, then "expectedContentLength" return -1. And "Content-Length" is absent from [response allHeaderFields].
