This is a code snippet that uploads a binary image file from an iOS device to a listening RESTful web service that answers to POST. Dispatch this method in a separate thread.

restfuluploadofpngfromios

(void)uploadMyNewPictureToWeb {

        //your web service that's on the lookout for the image
        NSMutableString *customWebPage = [NSMutableString stringWithString:@"your web service URL would go here"];
        NSURL *aUrl = [NSURL URLWithString:customWebPage];
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:aUrl];

        //this is your POST, PUT, whatever restful protocol you support
        [request setHTTPMethod:@"POST"];

        //set the content type
        //the spec calls for a unique string of characters as a separator, so use something random, but unique
        //also, I can't stress enough how important it is to get all the \r\n's correct
        NSString *boundary = @"DK39FJK4589FDKJSW893JKLR89DFJK238934IOSO";
        NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
        [request setValue:contentType forHTTPHeaderField:@"Content-Type"];

        //body
        NSMutableData *body = [NSMutableData data];

        //add all the textual params first (I'm going to assume you have some things to transmit other than just a photo
        //let's call them param1 and param2
        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", @"param1"] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"%@\r\n", _param1] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", @"param2"] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"%@\r\n", _param2] dataUsingEncoding:NSUTF8StringEncoding]];

        //now add the image data, remember in the original post, I used a button, you could get this from local documents storage or wherever
        NSData *imageData = UIImagePNGRepresentation(_profilePictureButton.imageView.image);
        if (imageData) {
            [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
            [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"; filename=\"mrkangaroo.png\"\r\n", @"mrkangaroo"] dataUsingEncoding:NSUTF8StringEncoding]];
            [body appendData:[[NSString stringWithFormat:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
            [body appendData:[NSData dataWithData:imageData]];
            [body appendData:[[NSString stringWithFormat:@"%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        }
        [body appendData:[[NSString stringWithFormat:@"--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

        //set the body to the request
        [request setHTTPBody:body];

        //set the content length
        NSString *postLength = [NSString stringWithFormat:@"%d", [body length]];
        [request setValue:postLength forHTTPHeaderField:@"Content-Length"];

        NSURLResponse *response;
        NSError *error;

        //send it and do something with the response...response parsing is left off here for simplicity
        NSData *myJSONNetworkData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

        //parsing response...
}