WP7 (windows phone 7) HttpWebRequest losing POST d

I'm sending a lot of POST data (over 5000 chars) and it seems that WP7 HttpWebRequest is losing some of the content in the process...

The data is a png converted to a byte array and after to a base64 string.

If my data is 4941 characters long, it will send only 1448 chars, the content length (verified with wireshark) of the request is fine (Content-Length: 4991).

How i send the data :

void SendPost()
{
    // Create the web request object
    HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
    webRequest.Method = "POST";
    webRequest.ContentType = "application/x-www-form-urlencoded";

    // Start the request
    webRequest.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), webRequest);

}

void GetRequestStreamCallback(IAsyncResult asynchronousResult)
{
    HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
    // End the stream request operation
    Stream postStream = webRequest.EndGetRequestStream(asynchronousResult);

    // Create the post data
    // Demo POST data (length = 3762)
    string postData = "data=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";

    //Actual code used
    /*for (int i = 0; i < paramNames.Count; i++)
    {
        // Parameter seperator
        if (i > 0)
        {
            postData += "&";
        }

         // Parameter data
         postData += paramNames[i] + "=" + paramValues[i];
    }*/

    byte[] byteArray = Encoding.UTF8.GetBytes(postData);

    // Add the post data to the web request
    postStream.Write(byteArray, 0, byteArray.Length);
    postStream.Close();

    // Start the web request
    webRequest.BeginGetResponse(new AsyncCallback(GetResponseCallback), webRequest);
}

void GetResponseCallback(IAsyncResult asynchronousResult)
{

    try
    {
        HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
        HttpWebResponse response;

        // End the get response operation
        response = (HttpWebResponse)webRequest.EndGetResponse(asynchronousResult);
        Stream streamResponse = response.GetResponseStream();
        StreamReader streamReader = new StreamReader(streamResponse);
        Response = streamReader.ReadToEnd();
        streamResponse.Close();
        streamReader.Close();
        response.Close();

    }
    catch (WebException e)
    {
            // Error treatment
            // ...
    }
}

How can I send my data entirely ?

Thank you !

In RunSat I send plenty more bytes than that using the code below - its similar to the code you've shown and it works fine (although I admit I mainly test on a real device)

            Stream requestStream = CurrentWebRequest.EndGetRequestStream(async);
            byte[] encodedBytes = Encoding.UTF8.GetBytes(payload);
            requestStream.Write(encodedBytes, 0, encodedBytes.Length);
            requestStream.Flush();
            requestStream.Close();

Depending on how expert you are with WireShark, it might not be telling you the whole truth - when you're looking at wireshark you will see the TCP level packets which (for ip4) commonly have 1448 bytes of payload - http://en.wikipedia.org/wiki/TCP_segmentation_offload - and I find it easy to miss the continuation packets. (I'm not a wireshark user, but have used ethereal a bit)

Update: I've run this code below

It works fine - you can see the upload at http://posttestserver.com/data/2011/05/12/03.29.331923823079

I recommend you stop messing about at the ethernet and TCP/IP packet levels with WireShark and take a look at your webservice.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace DemoProject
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
            SendPost();
        }

        void SendPost()
        {
            var url = "http://posttestserver.com/post.php";

            // Create the web request object
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
            webRequest.Method = "POST";
            webRequest.ContentType = "application/x-www-form-urlencoded";

            // Start the request
            webRequest.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), webRequest);    
        }

        void GetRequestStreamCallback(IAsyncResult asynchronousResult)
        {
            HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
            // End the stream request operation
            Stream postStream = webRequest.EndGetRequestStream(asynchronousResult);

            // Create the post data
            // Demo POST data 
            string postData = "data=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";

            byte[] byteArray = Encoding.UTF8.GetBytes(postData);

            // Add the post data to the web request
            postStream.Write(byteArray, 0, byteArray.Length);
            postStream.Close();

            // Start the web request
            webRequest.BeginGetResponse(new AsyncCallback(GetResponseCallback), webRequest);
        }

        void GetResponseCallback(IAsyncResult asynchronousResult)
        {    
            try
            {
                HttpWebRequest webRequest = (HttpWebRequest)asynchronousResult.AsyncState;
                HttpWebResponse response;

                // End the get response operation
                response = (HttpWebResponse)webRequest.EndGetResponse(asynchronousResult);
                Stream streamResponse = response.GetResponseStream();
                StreamReader streamReader = new StreamReader(streamResponse);
                var Response = streamReader.ReadToEnd();
                streamResponse.Close();
                streamReader.Close();
                response.Close();

            }
            catch (WebException e)
            {
                // Error treatment
                // ...
            }
        }
    }
}