Diese Frage wird ein nettes Tutorial für die http-Verbindung "POST" zwischen Iphone und asp.net-Server sein :) Ich versuche, ein Bild vom iPhone an den Asp.net-Server zu senden. Hier meine uploadImage Funktion in Objective-C:

<code>- (IBAction)uploadImage {
/*
 turning the image into a NSData object
 getting the image back out of the UIImageView
 setting the quality to 90
*/
NSData *imageData = UIImageJPEGRepresentation(image.image, 33);
// setting up the URL to post to
NSString *urlString = @"MyWebServiceUrl";

// setting up the request object now
NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];

/*
 add some header info now
 we always need a boundary when we post a file
 also we need to set the content type

 You might want to generate a random boundary.. this is just the same 
 as my output from wireshark on a valid html post
*/
NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];

/*
 now lets create the body of the post
*/
NSMutableData *body = [NSMutableData data];
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];    
[body appendData:[[NSString stringWithString:@"Content-Disposition: form-data; filepath=\"ProfilePic\"; filename=\"ipodfile\"\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]];
// setting the body of the post to the reqeust
[request setHTTPBody:body];

// now lets make the connection to the web
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];

NSLog(@"%@", returnString);
</code>

}

Und hier sind meine Webservice-Funktionen, die die gesendeten Daten analysieren und die Datei speichern:

<code>public class SaveData : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "text/plain";
        bool hasErrors = false;
        HttpFileCollection filesPosted = context.Request.Files;
        String filePath = context.Request.QueryString["filepath"];
        String fileName = context.Request.QueryString["filename"];
        try
        {
            if (String.IsNullOrEmpty(fileName) || String.IsNullOrEmpty(filePath) || filesPosted.Count <= 0)
                hasErrors = true;

            if (!hasErrors)
            {
                HttpContext.Current.Response.Write(WriteFile(filesPosted[0], filePath, fileName));
            }
            else
            {
                context.Response.Write("Failed: parsing error");
            }
        }
        catch (Exception ex)
        {
            context.Response.Write("Failed: exception error:::" + ex.Message);
        }

    }

    private string WriteFile(HttpPostedFile file, String filePath, String fileName)
    {
        System.IO.Directory.CreateDirectory(filePath);
        int counter = 0;
        string path = String.Format("{0}\\{1}.jpg", filePath, fileName);
        while (System.IO.File.Exists(path))
        {
            counter++;
            path = String.Format("{0}\\{1}-{2}.jpg", filePath, fileName, counter);
        }

        file.SaveAs(path);
        return path;
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}
</code>

Mein Problem kommt aus diesen beiden Zeilen

<code>        String filePath = context.Request.QueryString["filepath"];
        String fileName = context.Request.QueryString["filename"];
</code>

context.Request.QueryString gibt null zurück, sodass meine hasErrors falsch sind. Irgendwelche Ideen, wie man das behebt, werden so geschätzt, danke für alles.