.NetCore 接入微信JSSDK调用微信扫一扫

  public static class WxHelper
    {
        private static ILog log = LogManager.GetLogger(Startup.repository.Name, typeof(WxHelper));
        //获取AccessToken
        public static string Request_Url(string _appid, string _appsecret)
        {
            string _url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + _appid + "&secret=" + _appsecret;
            string method = "GET";
            HttpWebRequest request = WebRequest.Create(_url) as HttpWebRequest;
            CookieContainer cookieContainer = new CookieContainer();
            request.CookieContainer = cookieContainer;
            request.AllowAutoRedirect = true;
            request.Method = method;
            request.ContentType = "text/html";
            request.Headers.Add("charset", "utf-8");

            //发送请求并获取相应回应数据
            using HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            using Stream responseStream = response.GetResponseStream();
            using StreamReader sr = new StreamReader(responseStream, Encoding.UTF8);
            //返回结果网页（html）代码
            string content = sr.ReadToEnd();
            //由于微信服务器返回的JSON串中包含了很多信息，我们只需要将AccessToken获取就可以了，需要将JSON拆分
            String[] str = content.Split('"');
            content = str[3];
            return content;
        }

        //根据AccessToken来获取jsapi_ticket
        public static string Requestjsapi_ticket(string accesstoken)
        {

            string _accesstoken = accesstoken;
            string url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + _accesstoken + "&type=jsapi";
            string method = "GET";
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            CookieContainer cookieContainer = new CookieContainer();
            request.CookieContainer = cookieContainer;
            request.AllowAutoRedirect = true;
            request.Method = method;
            request.ContentType = "text/html";
            request.Headers.Add("charset", "utf-8");
            //发送请求并获取相应回应数据
            using HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            //直到request.GetResponse()程序才开始向目标网页发送Post请求
            using Stream responseStream = response.GetResponseStream();
            using StreamReader sr = new StreamReader(responseStream, Encoding.UTF8);
            //返回结果网页（html）代码
            string content = sr.ReadToEnd();
            //同样，返回的JSON中只要取出ticket的信息即可
            String[] str = content.Split('"');
            content = str[9];
            return content;
        }

        public static string Requestjsapi_ticket2(string accesstoken)
        {
                var response = string.Empty;
                var baseAddress = "https://api.weixin.qq.com";
                string url = $"{baseAddress}/cgi-bin/ticket/getticket?access_token={accesstoken}&type=jsapi";
                using var client = new HttpClient();
                client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "text/html");
                client.BaseAddress = new Uri(baseAddress);
                response = client.GetStringAsync(url).Result;
                String[] str = response.Split('"');
                var content = str[9];
                return content;
            //var response = string.Empty;
            //try
            //{
            //    var baseAddress = "https://api.weixin.qq.com";
            //    string url = $"{baseAddress}/cgi-bin/ticket/getticket?access_token={accesstoken}&type=jsapi";
            //    using var client = new HttpClient();
            //    client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "text/html");
            //    client.BaseAddress = new Uri(baseAddress);
            //    response = client.GetStringAsync(url).Result;
            //    String[] str = response.Split('"');
            //    var content = str[9];
            //    return content;
            //}
            //catch (Exception ex)
            //{
            //    log.Error($"{response};{ex}");
            //}
            //return response;
        }

        //接下来就是辅助工具类，生成随机字符串
        #region 字符串随机 CreatenNonce_str()
        private static string[] strs = new string[]
                                    {
                                    "a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z",
                                    "A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"
                                    };
        public static string CreatenNonce_str()
        {
            Random r = new Random();
            var sb = new StringBuilder();
            var length = strs.Length;
            for (int i = 0; i < 15; i++)
            {
                sb.Append(strs[r.Next(length - 1)]);
            }
            return sb.ToString();
        }
        #endregion

        //生成时间戳，备用
        #region 时间戳生成 CreatenTimestamp()
        public static long CreatenTimestamp()
        {
            return (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
        }
        #endregion

        //获取签名，这里的三个参数分别为前面生成的ticket，随机字符串以及时间戳
        #region 获取签名 GetSignature()
        public static string GetSignature(string jsapi_ticket, string noncestr, long timestamp, string url)
        {

            var string1Builder = new StringBuilder();
            string1Builder.Append("jsapi_ticket=").Append(jsapi_ticket).Append("&")
                          .Append("noncestr=").Append(noncestr).Append("&")
                          .Append("timestamp=").Append(timestamp).Append("&")
                          .Append("url=").Append(url.IndexOf("#") >= 0 ? url.Substring(0, url.IndexOf("#")) : url);
            return SHA1(string1Builder.ToString());
        }
        #endregion


        //最后就是SHA1的加密算法工具
        #region 加密签名算法 SHA1(content)
        //加密签名算法
        public static string SHA1(string content)
        {
            return SHA1(content, Encoding.UTF8);

        }
        //加密签名
        public static string SHA1(string content, Encoding encode)
        {
            try
            {
                SHA1 sha1 = new SHA1CryptoServiceProvider();
                byte[] bytes_in = encode.GetBytes(content);
                byte[] bytes_out = sha1.ComputeHash(bytes_in);
                sha1.Dispose();
                string result = BitConverter.ToString(bytes_out);
                result = result.Replace("-", "");
                return result;
            }
            catch (Exception ex)
            {
                throw new Exception("SHA1加密出错：" + ex.Message);
            }
        }
        #endregion
    }

 public class MemoryCacheHelper
    {
        public static readonly IMemoryCache _memoryCache = new MemoryCache(new MemoryCacheOptions());

        /// <summary>
        /// 是否存在此缓存
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public static bool Exists(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));
            object v = null;
            return _memoryCache.TryGetValue<object>(key, out v);
        }

        /// <summary>
        /// 取得缓存数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="key"></param>
        /// <returns></returns>
        public static T GetCache<T>(string key) where T : class
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));


            T v = null;
            _memoryCache.TryGetValue<T>(key, out v);


            return v;
        }

        /// <summary>
        /// 设置缓存,绝对过期
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <param name="expirationMinute">间隔分钟</param>
        /// CommonManager.CacheObj.Save<RedisCacheHelper>("test", "RedisCache works!", 30);
        public static void SetCache(string key, object value, double expirationMinute)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));
            if (value == null)
                throw new ArgumentNullException(nameof(value));

            object v = null;
            if (_memoryCache.TryGetValue(key, out v))
                _memoryCache.Remove(key);
            DateTime now = DateTime.Now;
            TimeSpan ts = now.AddMinutes(expirationMinute) - DateTime.Now;
            _memoryCache.Set<object>(key, value, ts);
        }

        /// <summary>
        /// 释放
        /// </summary>
        public static void Dispose()
        {
            if (_memoryCache != null)
                _memoryCache.Dispose();
            //GC.SuppressFinalize(this);
        }
    }

 //引入wxjssdk
 <script src="http://res.wx.qq.com/open/js/jweixin-1.1.0.js"> </script> 
 	<script>
	 wx.config({
        debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。  
        appId: '@ViewBag.appid', // 必填，公众号的唯一标识  
        timestamp: '@ViewBag.timestamp', // 必填，生成签名的时间戳  
        nonceStr: '@ViewBag.noncestr', // 必填，生成签名的随机串  
        signature: '@ViewBag.sinature',// 必填，签名  
        jsApiList: ['checkJsApi',
        //这里的接口在官方文档中都有涉及，我们只需要调用微信扫一扫即可
                    //'chooseImage',
                    //'previewImage',
                    // 'uploadImage',
                    // 'downloadImage',
                    //  'getNetworkType',//网络状态接口
                    //  'openLocation',//使用微信内置地图查看地理位置接口
                    //  'getLocation', //获取地理位置接口
                    //  'hideOptionMenu',//界面操作接口1
                    //  'showOptionMenu',//界面操作接口2
                    //  'closeWindow',  界面操作接口3
                    //  'hideMenuItems',界面操作接口4
                    //  'showMenuItems',界面操作接口5
                    //  'hideAllNonBaseMenuItem',界面操作接口6
                    //  'showAllNonBaseMenuItem',界面操作接口7
                      'scanQRCode'// 微信扫一扫接口
        ]  
        });

 <!--开始扫描  在合适的地方调用此方法唤醒扫一扫-->
        function scan(){
            wx.ready(function () {
                wx.scanQRCode({
                    needResult: 1,
                    desc: 'scanQRCode desc',
                    success: function (res) {}
					 });
					  })
        }
	</script>

  private readonly static object lockobj = new object();
 public ActionResult Index()
        {
			//此处若是测试可以写死
            //配置文件获取配置信息 
            var appid = configuration.GetValue<string>("appid");
            var appsecret = configuration.GetValue<string>("appsecret");
            //返回调用扫一扫需要的配置信息
            //获取ACCESS_TOKEN
            string _token = string.Empty;
            string _finalticket= string.Empty;

            if (!MemoryCacheHelper.Exists("_token"))
            {
                lock (lockobj)
                {
                    if (!MemoryCacheHelper.Exists("_token"))
                    {
                        _token = WxHelper.Request_Url(appid, appsecret);
                        //缓存token
                        MemoryCacheHelper.SetCache("_token", _token, 115);
                    }
                    else
                        _token = MemoryCacheHelper.GetCache<string>("_token");
                }
            }
            else
            {
                _token = MemoryCacheHelper.GetCache<string>("_token");
            }
            //获取Ticket
            string _ticket = WxHelper.Requestjsapi_ticket2(_token);
            //获取ticket
            _finalticket = _ticket;
            //获取noncestr
            string _noncestr = WxHelper.CreatenNonce_str();
            //获取timestamp
            long _timestamp = WxHelper.CreatenTimestamp();
            //获取sinature
            string _url = HttpContext.Request.GetDisplayUrl();
            string _sinature = WxHelper.GetSignature(_finalticket, _noncestr, _timestamp, _url).ToLower();

            ViewBag.appid = configuration.GetValue<string>("appid");
            ViewBag.timestamp = _timestamp;
            ViewBag.noncestr = _noncestr;
            ViewBag.sinature = _sinature;
            return View();
        }