namespace WEF
{
  /// <summary>
  /// Token 的摘要说明
  /// </summary>
  public class Token : IHttpHandler
  {

    public void ProcessRequest(HttpContext context)
    {
      ProcesyanzhengsRequest(context);//执行下面方法

    }

    public bool IsReusable
    {
      get
      {
        return false;
      }
    }

    public void ProcesyanzhengsRequest(HttpContext context)
    {
      context.Response.ContentType = "text/plain";
      string token = " ";//输入你上面自己编写的Token
      if (string.IsNullOrEmpty(token))
      {
        return;
      }　　　　　　//取到Token接收到的值
      string echoString = HttpContext.Current.Request.QueryString["echoStr"];
      string signature = HttpContext.Current.Request.QueryString["signature"];
      string timestamp = HttpContext.Current.Request.QueryString["timestamp"];
      string nonce = HttpContext.Current.Request.QueryString["nonce"];
      if (CheckSignature(token, signature, timestamp, nonce)) //判断验证是否正确
      {
        if (!string.IsNullOrEmpty(echoString))  正确返回微信服务器
        {
          HttpContext.Current.Response.Write(echoString);
          HttpContext.Current.Response.End();
        }

      }

    }
    /// <summary>
    /// 验证微信签名
    /// </summary>
    public static bool CheckSignature(string token, string signature, string timestamp, string nonce)
    {
      string[] ArrTmp = { token, timestamp, nonce };
      //字典排序
      Array.Sort(ArrTmp);
      //拼接
      string tmpStr = string.Join("", ArrTmp);
      //sha1验证
      tmpStr = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(tmpStr, "SHA1");
      //tmpStr = Membership.CreateUser(tmpStr, "SHA1");
      tmpStr = tmpStr.ToLower();
      if (tmpStr == signature) //如果计算后得到的数值与传过来的数值相等
      {
        return true;  //返回正确
      }
      else
      {
        return false; //不相等 返回错误
      }
    }

  }
}

<connectionStrings>
<add name="SqlConnectionString"
connectionString="server=.;database=WEF;uid=sa;pwd=1@#;Enlist=true;Pooling=true;Max Pool Size=300;Min Pool Size=0;Connection Lifetime=300;user id=sa;packet size=1000"/>
</connectionStrings>