NSData and Uploading Images via POST in iOS

This code works in my app. If you're not using ARC you'll need to modify the code to release anything alloc'ed.

// create requestNSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];                                    [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];[request setHTTPShouldHandleCookies:NO];[request setTimeoutInterval:30];[request setHTTPMethod:@"POST"];// set Content-Type in HTTP headerNSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];[request setValue:contentType forHTTPHeaderField: @"Content-Type"];// post bodyNSMutableData *body = [NSMutableData data];// add params (all params are strings)for (NSString *param in _params) {    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", param] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"%@\r\n", [_params objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];}// add image dataNSData *imageData = UIImageJPEGRepresentation(imageToPost, 1.0);if (imageData) {    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"image.jpg\"\r\n", FileParamConstant] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithString:@"Content-Type: image/jpeg\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:imageData];    [body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];}[body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];// setting the body of the post to the reqeust[request setHTTPBody:body];// set URL[request setURL:requestURL];

i hope this code will help some body else ...

//create requestNSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];//Set Params[request setHTTPShouldHandleCookies:NO];[request setTimeoutInterval:60];[request setHTTPMethod:@"POST"];//Create boundary, it can be anythingNSString *boundary = @"------VohpleBoundary4QuqLuM1cE5lMwCy";// set Content-Type in HTTP headerNSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];[request setValue:contentType forHTTPHeaderField: @"Content-Type"];// post bodyNSMutableData *body = [NSMutableData data];//Populate a dictionary with all the regular values you would like to send.NSMutableDictionary *parameters = [[NSMutableDictionary alloc] init];[parameters setValue:param1 forKey:@"param1-name"];[parameters setValue:param2 forKey:@"param2-name"];[parameters setValue:param3 forKey:@"param3-name"];// add params (all params are strings)for (NSString *param in parameters) {    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", param] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"%@\r\n", [parameters objectForKey:param]] dataUsingEncoding:NSUTF8StringEncoding]];}NSString *FileParamConstant = @"imageParamName";NSData *imageData = UIImageJPEGRepresentation(imageObject, 1);//Assuming data is not nil we add this to the multipart formif (imageData){    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"image.jpg\"\r\n", FileParamConstant] dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:[@"Content-Type:image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];    [body appendData:imageData];    [body appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];}//Close off the request with the boundary[body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];// setting the body of the post to the request[request setHTTPBody:body];// set URL[request setURL:[NSURL URLWithString:baseUrl]];[NSURLConnection sendAsynchronousRequest:request                                   queue:[NSOperationQueue mainQueue]                       completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {                           NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;                           if ([httpResponse statusCode] == 200) {                               NSLog(@"success");                           }                       }];

Take a look at Apple's SimpleURLConnections example project. You can use the PostController from there with a few modifications.

However - it's not exactly simple. The difference to the solution above is that Apple's is using a stream to stream the file to the server. That's much more memory-friendly than keeping the encoded image data around for the duration of the upload. It's also way more complicated.