Question

I am trying to send images and text from an iPhone application to a asp.net webpage.

By following this example I now have the following method in xcode for uploading an image:

- (BOOL) uploadData {
    NSData *imageData = UIImageJPEGRepresentation([serviceForm image], 0.9);
    NSString *urlString = @"http://someUrl/SubmitSchema.ashx";
    NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
    [request setURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"POST"];

    NSString *boundary = @"---------------------------14737809831466499882746641449";
    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 stringWithString:@"Content-Disposition: form-data; name=\"userfile\"; filename=\"ipodfile.jpg\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

    [body appendData:[NSData dataWithData:imageData]];

    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];

    [request setHTTPBody:body];

    NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
    NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];

    BOOL success = [returnString isEqualToString:@"ok"];
    [returnString release];

    return success;
}

At the bottom on the same article there is a suggestion about creating an asp.net generic handler. Based on this, I have the following simple code for saving the image:

public void ProcessRequest(HttpContext context)
{
    context.Response.ContentType = "text/plain";
    foreach (var name in context.Request.Files.AllKeys)
    {
        var file = context.Request.Files.Get(name);
        SaveFile(file);
    }
}

private void SaveFile(HttpPostedFile file)
{
    var fileName = Path.GetFileName(file.FileName);
    var path = "C:\\Test\\" + fileName;

    file.SaveAs(path);
}

This works and the image is saved, but I have not yet managed to include a string of text in the same post. The text I want to send can be quite long, and I suppose it is better to include this in the posted data rather than as a query string?

How would you add some text to the posted data and read it in .net?

Answer 1

I’m not an Objective-C expert but from a little Googling I found a discussion and a working example of sending a file and form fields in a single request.

On the server, you can pull the data out again on the other side using:

string data = Request.Form["name"];

If you get stuck, Fiddler is a great tool for sniffing HTTP requests.