public class Config
    {
        public static IEnumerable<IdentityResource> GetIdentityResources()
        {
            return new List<IdentityResource>
            {
                new IdentityResources.OpenId(),
                new IdentityResources.Profile(),
            };
        }

        public static IEnumerable<ApiResource> GetApiResources()
        {
            return new List<ApiResource>
            {
                new ApiResource("Library.Api","Library Api")
                {
                    ApiSecrets = {new Secret("secret".Sha256())} ,
                    Scopes = { new Scope("api1")}

                }
            };

        }

        // clients want to access resources (aka scopes)
        public static IEnumerable<Client> GetClients()
        {
            // client credentials client
            return new List<Client>
            {
                #region ClientCredentials
                // machine to machine client
                new Client
                {
                    ClientId = "client.identity",
                    ClientSecrets = { new Secret("secret".Sha256()) },

                    AllowedGrantTypes = GrantTypes.ClientCredentials,
                    // scopes that client has access to
                    AllowedScopes = { "api1" }
                },
                #endregion 

                #region  ResourceOwnerPassword
                // resource owner password grant client
                new Client
                {
                    ClientId = "password.identity",
                    AllowedGrantTypes = GrantTypes.ResourceOwnerPassword,
                    AccessTokenLifetime = 2592000,          //15天
                    //AccessTokenLifetime = 60,          //测试60秒过期
                    SlidingRefreshTokenLifetime = 2592000,  //30天
                    AllowOfflineAccess = true,              //返回refreshToken
                    AlwaysSendClientClaims = true,          //
                    UpdateAccessTokenClaimsOnRefresh = true,
                    AbsoluteRefreshTokenLifetime = 0,       // refreshToken不过期
                    RefreshTokenExpiration = TokenExpiration.Sliding,
                    AlwaysIncludeUserClaimsInIdToken = true,
                    ClientSecrets ={
                        new Secret("secret".Sha256())
                    },
                    AllowedScopes = {
                        "api1",
                        StandardScopes.OfflineAccess, //如果要获取refresh_tokens ,必须在scopes中加上OfflineAccess
                        StandardScopes.OpenId,//如果要获取id_token,必须在scopes中加上OpenId和Profile，id_token需要通过refresh_tokens获取AccessToken的时候才能拿到（还未找到原因）
                        StandardScopes.Profile//如果要获取id_token,必须在scopes中加上OpenId和Profile
                      },
                },
                #endregion
                
            };
        }

    }

POST /connect/introspect
  Authorization: Basic sValue
  
  token=<token>

var sValue = Convert.ToBase64String(Encoding.UTF8.GetBytes(string.Format("{0}:{1}", "Library.Api", "secret")));

        public async Task<ActionResult> ValidToken(string token)
        {
            ApiResultModel apiResult = new ApiResultModel();

            var CurrentRequest = httpContextAccessor.HttpContext.Request;
            string sUrl = CurrentRequest.Scheme + "://" + CurrentRequest.Host.Value;

            var client = new HttpClient();

            var disco = await client.GetDiscoveryDocumentAsync(sUrl);

            var result = await client.IntrospectTokenAsync(new TokenIntrospectionRequest
            {
                Address = disco.IntrospectionEndpoint,

                ClientId = "Library.Api", // this is your APi Resource name
                ClientSecret = "secret",  // this is your APi resource secret
                Token = token
            });

            if (result.IsError)
            {
                apiResult.Code = ResultCode.Error;
                apiResult.Data = result.Error;
                return new JsonResult(apiResult);
            }

            apiResult.Code = ResultCode.Success;
            apiResult.Data = result.IsActive;
            return new JsonResult(apiResult);

        }

public class ApiResultModel
    {
        public ResultCode Code { get; set; }
        public string Message { get; set; }
        public object Data { get; set; }

        public ApiResultModel() { }
        public ApiResultModel(ResultCode code,string message,object data)
        {
            Code = code;
            Message = message;
            Data = data;
        }
    }

    public enum ResultCode
    {
        Success = 0,
        Error = 1,
    }