IdentityServer4 发现端点

        static IDiscoveryCache _cache = new DiscoveryCache("服务器基地址");

            var disco = await _cache.GetAsync();
            if (disco.IsError) throw new Exception(disco.Error);

            var client = new HttpClient();
　　　　　　//这里举例密码获取token
            var response = await client.RequestPasswordTokenAsync(new PasswordTokenRequest
            {
                Address = disco.TokenEndpoint,
                ClientId = "roclient.reference",
                ClientSecret = "secret",

                UserName = "bob",
                Password = "bob",
                Scope = "scope4.scope"
            });

            if (response.IsError) throw new Exception(response.Error);
            return response;