.NET微信网页开发之通过UnionID机制解决多应用用户帐号统一问题

public class WeChatLogin : Controller
    {
        /// <summary>
        /// 获取用户UnionID（用户统一标识）
        /// </summary>
        /// <param name="state">自定义参数</param>
        /// <param name="code">通过用户授权后得到的code</param>
        /// <returns></returns>
        public async Task<Response> GetWeChatUnionID(string state, string code)
        {
            string appId = "YourAppId";
            string appSecret = "YourAppSecret";
            string requestUrl = $"https://api.weixin.qq.com/sns/oauth2/access_token?appid={appId}&secret={appSecret}&code={code}&grant_type=authorization_code";
            using (var httpClient = new HttpClient())
            {
                var httpRequest = new HttpRequestMessage(HttpMethod.Get, requestUrl);
                using (var response = await httpClient.SendAsync(httpRequest))
                {
                    if (response.IsSuccessStatusCode)
                    {
                        var responseString = await response.Content.ReadAsStringAsync();
                        var responseData = JsonConvert.DeserializeObject<WeChatTokenResponse>(responseString);
                        return new Response
                        {
                            Code = 1,
                            Message = responseData.UnionId
                        };
                    }
                    else
                    {
                        var errorResponseString = await response.Content.ReadAsStringAsync();
                        var errorData = JsonConvert.DeserializeObject<ErrorResponse>(errorResponseString);
                        return new Response
                        {
                            Code = 0,
                            Message = $"Failed to get access token: {errorData.ErrMsg}"
                        };
                    }
                }
            }
        }
    }
    public class WeChatTokenResponse
    {
        [JsonProperty("access_token")]
        public string AccessToken { get; set; }
        [JsonProperty("expires_in")]
        public int ExpiresIn { get; set; }
        [JsonProperty("refresh_token")]
        public string RefreshToken { get; set; }
        [JsonProperty("openid")]
        public string OpenId { get; set; }
        [JsonProperty("scope")]
        public string Scope { get; set; }
        [JsonProperty("is_snapshotuser")]
        public int IsSnapshotUser { get; set; }
        [JsonProperty("unionid")]
        public string UnionId { get; set; }
    }
    public class ErrorResponse
    {
        [JsonProperty("errcode")]
        public int ErrCode { get; set; }
        [JsonProperty("errmsg")]
        public string ErrMsg { get; set; }
    }