/// <summary>
        ///
        /// </summary>
        /// <param name="httpContext"></param>
        /// <returns></returns>
        public Task Invoke(HttpContext httpContext)
        {
            //检测是否包含'Authorization'请求头
            if (!httpContext.Request.Headers.ContainsKey("Authorization"))
            {
                return(_next(httpContext));
            }
            var tokenHeader = httpContext.Request.Headers["Authorization"].ToString();

            TokenModelJWT tm = JwtHelper.SerializeJWT(tokenHeader);

            //授权
            var claimList = new List <Claim>();
            var claim     = new Claim(ClaimTypes.Role, tm.Role);

            claimList.Add(claim);
            var identity  = new ClaimsIdentity(claimList);
            var principal = new ClaimsPrincipal(identity);

            httpContext.User = principal;

            return(_next(httpContext));
        }