上传带有参数的文件（图像，pdf）到服务器
我想上传1pdf文件和图片数组。 我可以上传1pdf和2jpg文件，如果jpg文件超过两个我得到的消息：
错误域= NSCocoaErrorDomain代码= 3840“操作无法完成。（cocoa错误3840.）”（没有值。）UserInfo = 0x174268000 {NSDebugDescription =没有值。}
为什么发生这种情况？ 另外我用POSTMANtesting了服务器，它工作的很好。
NSURL *URL = [NSURL URLWithString:constFileUploadURL]; NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:URL]; [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData]; [request setHTTPShouldHandleCookies:NO]; [request setTimeoutInterval:60]; [request setHTTPMethod:@"POST"]; NSString *boundary = @"0xLhTaLbOkNdArZ"; NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary]; [request addValue:contentType forHTTPHeaderField:@"Content-Type"]; NSMutableData *body = [NSMutableData data]; [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"user_id\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; NSString *userid = [NSString stringWithFormat:@"%li",userID]; [body appendData:[userid dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"key\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[constBackendKey dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; for (NSData *data in arrayWithFiles) { NSString *fileName; if ([arrayWithFiles indexOfObject:data] == 0) { [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]]; fileName = @"Content-Disposition: form-data; name=\"files\"; filename=\"PdfFile.pdf\"\r\n"; [body appendData:[fileName dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[NSData dataWithData:data]]; [body appendData:[[NSString stringWithString:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; } else { [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"files%ld\"; filename=\"image%ld.jpg\"\r\n",[arrayWithFiles indexOfObject:data],[arrayWithFiles indexOfObject:data]] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; [body appendData:[NSData dataWithData:data]]; [body appendData:[[NSString stringWithString:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]]; } } [body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]]; [request setHTTPBody:body]; _connection = [NSURLConnection connectionWithRequest:request delegate:self]; 鳕鱼工作，问题在服务器端。 file upload50MB，邮政大小8MB。