向远程服务器发送并接受文件

/// <summary>
/// 发送文件
/// </summary>
public static void PostBinaryData()
{
    string notice = Convert.ToString(Guid.NewGuid());
    string sign = MD5Helper.Encrypt("zoversoft" + notice);
    string url = string.Format("http://www.xx.com/File/SaveImageData?childFile={0}&sign={1}&notice={2}", "lk", sign, notice);
    byte[] bytes = System.IO.File.ReadAllBytes(@"F:\微信应用logo\消息.jpg");
    HttpWebRequest wRequest = (HttpWebRequest)WebRequest.Create(url);
    wRequest.ContentType = "multipart/form-data";
    wRequest.ContentLength = bytes.Length;
    wRequest.Method = "POST";
    using (Stream stream = wRequest.GetRequestStream())
    {
        stream.Write(bytes, 0, bytes.Length);
        using (HttpWebResponse wResponse = (HttpWebResponse)wRequest.GetResponse())
        {
            using (StreamReader sReader = new StreamReader(wResponse.GetResponseStream(), System.Text.Encoding.UTF8))
            {
                Console.Write(sReader.ReadToEnd());
                Console.ReadKey();
            }
        }
    }
} 

/// <summary>
/// 接收文件
/// </summary>
/// <param name="childFile">文件夹</param>
/// <param name="sign">签名</param>
/// <param name="notice">随机字符串</param>
/// <returns>结果/文件路径</returns>
[HttpPost]
public JsonResult SaveImageData(string childFile, string sign, string notice)
{
    try
    {
        if (MD5Helper.Encrypt("zoversoft" + notice) == sign)
        {
            string filePath = IPublicVar.WebDownPath + childFile;
            if (System.IO.Directory.Exists(filePath) == false)
            {
                System.IO.Directory.CreateDirectory(filePath);
            }
            string fileName = string.Format("{0:yyyyMMdd}", DateTime.Now) + sign + ".jpg";
            using (Bitmap img = new Bitmap(Request.InputStream))
            {
                img.Save(filePath + @"\" + fileName);
                return Json(childFile + "/" + fileName);
            }
        }
        else
        {
            return Json("0");
        }
    }
    catch
    {
        return Json("-1");
    }
}