Send a content type “multipart/form-data” request from C#

"cs">private string GetPostData() 
{ 
    string boundary = "--" + this._Boundary; 
    int arrReqs = this._ParamsCollection.Count * 5; 
    string[] auxReqBody = new string[arrReqs]; 
    int count = 0; 
    foreach(ParamsStruct par in this._ParamsCollection) 
    { 
        auxReqBody[count] = boundary; 
        count++; 
        switch (par.Type) 
        { 
            case ParamsStruct.ParamType.File: 
            { 
                auxReqBody[count] = "Content-Disposition: file; name=\"" + par.Name + "\"; filename=\"" + par.GetOnlyFileName() + "\""; 
                count++; 
                auxReqBody[count] = "Content-Type: text/plain"; 
                count++; 
                auxReqBody[count] = ""; 
                count++; 
                auxReqBody[count] = par.StringValue; 
                count++; 
                break; 
            } 
            case ParamsStruct.ParamType.Parameter: 
            default: 
            { 
                auxReqBody[count] = "Content-Disposition: form-data; name=\"" + par.Name + "\""; 
                count++; 
                auxReqBody[count] = ""; 
                count++; 
                auxReqBody[count] = par.StringValue; 
                count++; 
                break; 
            } 
        } 
    } 
    auxReqBody[count] = boundary; 
    count++; 
    string requestBody = String.Join("\r\n",auxReqBody); 
    return requestBody;
} 

"cs">public void PostData ()
{ 
    //Set URL 

    Uri urlUri = new Uri(_URL); 
    //Encoding postData 

    ASCIIEncoding encoding = new ASCIIEncoding(); 
    string postData = this.GetPostData(); 
    byte[] buffer = encoding.GetBytes( postData ); 
    // Prepare web request... 

    HttpWebRequest myRequest =(HttpWebRequest)WebRequest.Create(urlUri); 
    // We use POST ( we can also use GET ) 

    myRequest.Method = this._Method; 
    myRequest.AllowWriteStreamBuffering = true; 
    // Set the content type to a FORM 

    string auxContent = this._ContentType; 
    if (this._Boundary.Length > 0) 
        auxContent += "boundary=" + this._Boundary; 
    myRequest.ContentType = auxContent; 
    // Get length of content 

    myRequest.Accept = this._Accept; 
    myRequest.ContentLength = buffer.Length; 
    // Get request stream 

    Stream newStream = myRequest.GetRequestStream(); 
    // Send the data. 

    newStream.Write(buffer,0,buffer.Length); 
    // Close stream 

    newStream.Close(); 
    _myHttpWebResponse= (HttpWebResponse)myRequest.GetResponse(); 
    // Set the response to ResponseStream property 

    this._ResponseStream = _myHttpWebResponse.GetResponseStream();
} 

"cs">public string ResponseString
{ 
    get 
    { 
        string resultData = ""; 
        StreamReader streamRead = new StreamReader( _ResponseStream ); 
        Char[] readBuffer = new Char[256]; 
        // Read from buffer 

        int count = streamRead.Read( readBuffer, 0, 256 ); 
        while (count > 0) 
        { 
            // get string 

            resultData += new String( readBuffer, 0, count); 
            // Write the data 

            Console.WriteLine( resultData ); 
            // Read from buffer 

            count = streamRead.Read( readBuffer, 0, 256); 
        } 
        // Release the response object resources. 

        streamRead.Close(); 
        return resultData; 
    }
}