Asp.Net Mvc对接微信公共号

public class WxApiController : ApiController
    {
        private string _token = "weixinYWTX";

        /// <summary>
        /// 验证签名，检验是否是从微信服务器上发出的请求
        /// </summary>
        /// <param name="model">请求参数模型 Model</param>
        /// <returns>是否验证通过</returns>
        private bool CheckSignature(string signature, string timestamp, string nonce, string echostr)
        {
            string tempStr;
            //创建数组，将Token,timestamp,nonce三个数据加入数组
            string[] array = { _token, timestamp, nonce };
            //进行排序
            Array.Sort(array);
            //拼接为一个字符串
            tempStr = string.Join("", array);

            tempStr = FormsAuthentication.HashPasswordForStoringInConfigFile(tempStr, "SHA1").ToLower();
            //判断signature是否正确
            if (tempStr.Equals(signature))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        [HttpGet]
        public HttpResponseMessage Vaild(string signature, string timestamp, string nonce, string echostr)
        {

            HttpResponseMessage result;
            //通过验证
            if (CheckSignature(signature, timestamp, nonce, echostr))
            {
                if (!string.IsNullOrEmpty(echostr))
                {
                    //返回纯文本text/plain  ,返回json application/json  ,返回xml text/xml
                    result = MessageHelper.ResponseText(echostr);
                }
                else
                {
                    result = MessageHelper.ResponseText("");
                }
            }
            else
            {
                result = MessageHelper.ResponseText("");
            }
            return result;
        }
}