Windows Phone 8 Http request with custom header

I want to send a HTTP PUT request to a WCF server from Windows Phone 8, and for identification I have to send a custom header. (assume "mycustomheader" = "abc") I was using `WebClient` so far, but the `Webclient.Headers` seems not to have an `Add` method, so it is not possible to send headers other then the ones in `HttpRequestHeader` enum. Is there any way to do this with `WebClient`? I saw it is possible to set a custom header with `HttpWebRequest` class, but I just can't get it to do anything at all. My test code (basically the sample copied from http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.begingetrequeststream.aspx): ``` public void dosth() { HttpWebRequest wr = (HttpWebRequest)WebRequest.Create("http://mycomputer/message"); wr.Method = "PUT"; wr.ContentType = "application/x-www-form-urlencoded"; wr.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), wr); allDone.WaitOne(); } private static void GetRequestStreamCallback(IAsyncResult asynchronousResult) { HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState; Stream postStream = request.EndGetRequestStream(asynchronousResult); string postData = "{'Command': { 'RequestType' : 'Status', 'Test' : '1' }}"; byte[] byteArray = Encoding.UTF8.GetBytes(postData); postStream.Write(byteArray, 0, postData.Length); postStream.Close(); request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request); } private static void GetResponseCallback(IAsyncResult asynchronousResult) { HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState; HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult); Stream streamResponse = response.GetResponseStream(); StreamReader streamRead = new StreamReader(streamResponse); string responseString = streamRead.ReadToEnd(); streamResponse.Close(); streamRead.Close(); response.Close(); allDone.Set(); } ``` As I can see with wireshark: nothing is arriving at my computer (same url and everything works fine with `WebClient` .. except for the custom header). In debugging I can see the `GetRequestStreamCallback` being fired and running through. But it never arrives in the `GetResponseCallback`. Most stuff I find regarding this refers to methods like `GetResponse()` that seem not to be available on Whats is the way to go here? Is it possible to get the `HttpWebRequest` to work, or is there some workaround to get the custom header set in `WebClient` or is there even another better way? edit: webclient code: ``` WebClient wc = new WebClient(); wc.Headers[HttpRequestHeader.ContentLength] = data.Length.ToString(); wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded"; wc.UploadStringAsync(new Uri("http://mycomputer/message"), "PUT", data); ``` sends the correct data to the correct url. However setting custom header seems not to be possible. (even tried \r\n inside a header ... but this is not allowed and throws exception)