.NET 微信Token验证和消息接收和回复

 public class wxXmlModel
    {
        public string ToUserName { get; set; }
        public string FromUserName { get; set; }
        public string CreateTime { get; set; }
        public string MsgType { get; set; }
        public string Content { get; set; }
        public string MsgId { get; set; }

    }

  public string Token = "Token";

        protected void Page_Load(object sender, EventArgs e)
        {
            string echoStr = Request.QueryString["echoStr"];



            if (CheckSignature() && !string.IsNullOrEmpty(echoStr))
            {
                Response.Write(echoStr);
                Response.End();
            }
            else { 
                //如果没有接收到echostr说明不在是使用token验证
                //接收微信发送过来的xml消息并且解析
                 Stream requestSream=HttpContext.Current.Request.InputStream;
                byte[] requestByte=new byte[requestSream.Length];
                requestSream.Read(requestByte,0,(int)requestSream.Length);
                string requestStr=Encoding.UTF8.GetString(requestByte);

                if(!string.IsNullOrEmpty(requestStr))
                {
                    //封装请求类
                     XmlDocument requestDocXml=new XmlDocument();
                    requestDocXml.LoadXml(requestStr);
                    XmlElement rootElement=requestDocXml.DocumentElement;
                    wxXmlModel wxXmlModel=new wxXmlModel();
                    wxXmlModel.ToUserName=rootElement.SelectSingleNode("ToUserName").InnerText;
                    wxXmlModel.FromUserName=rootElement.SelectSingleNode("FromUserName").InnerText;
                    wxXmlModel.CreateTime=rootElement.SelectSingleNode("CreateTime").InnerText;
                    wxXmlModel.MsgType=rootElement.SelectSingleNode("MsgType").InnerText;
                    switch(wxXmlModel.MsgType)
                    {
                        case "text":
                            wxXmlModel.Content=rootElement.SelectSingleNode("Content").InnerText;
                            break;
                        default:
                            break;
                       
                    }
                 string      xmlMsg = "<xml>" + "<ToUserName><![CDATA[" + wxXmlModel.FromUserName+ "]]></ToUserName>"
                       + "<FromUserName><![CDATA[" + wxXmlModel.ToUserName + "]]></FromUserName>"
                       + "<CreateTime>" + DateTime.Now + "</CreateTime>"
                       + "<MsgType><![CDATA[text]]></MsgType>"
                       + "<Content><![CDATA["+wxXmlModel.Content+"]]></Content>"
                       + "</xml>";

                   Response.Write(xmlMsg);
                }
            }
        }
 private bool CheckSignature()
        {
            string signature = Request.QueryString["signature"];
            string timestamp = Request.QueryString["timestamp"];
            string nonce = Request.QueryString["nonce"];
          
            string[] arrTmp = { Token, timestamp, nonce };
            Array.Sort(arrTmp);
            string tmpStr = string.Join("", arrTmp);
            tmpStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");
            if (tmpStr != null)
            {
                tmpStr = tmpStr.ToLower();
                return tmpStr == signature;
            }
            return false;
        }