直接上程式碼

說明：因為微信的jsapi_ticket和token有時效性（7200秒）但微信那邊有限制你不能頻繁訪問，所以，我這裡是將這兩個引數存放至資料庫的，為避免剛好到7200秒時造成的分享失效，所以，在從資料庫查詢的時候，時效失效時間比較是比較的5000秒
注意：我這種寫法雖然可以實現功能，但是不建議使用這種方式，因為js部分是通過後臺註冊到前端的，如果與前端某個js有衝突，或者前端有js報錯，那麼註冊部分的js就不會接著往下執行。正確寫法是寫到js裡面或者直接寫到頁面裡面
微信分享的核心就是帶著appid等引數進行兩次介面對接獲取引數。

前臺需引用的js：
<%--微信分享相關js--%>
<script src="http://res.wx.qq.com/open/js/jweixin-1.2.0.js"
 
></script>

後臺部分程式碼：
private void RegisterWeiXinShareScript()
        {
            string aaa = CreateTimeStamp().ToString();
            //公眾號的應用ID  
            string appid = "wxxxxxxxxxxxx";
            //公眾號的應用金鑰  
            string secret = "xxxxxxxxxxxxxx";
            //生成簽名的時間戳  
            TimeSpan ts = DateTime.Now - DateTime.Parse("1970-01-01 00:00:00"
 
);
            string timestamp = ts.TotalSeconds.ToString().Split('.')[0]; 
            //生成簽名的隨機串  
            string nonceStr = Utils.Number(6);
            //微信access_token，用於獲取微信jsapi_ticket  
            string token = GetAccess_token(appid, secret);
            if (string.IsNullOrWhiteSpace(token))
            {
               string
 
 tokenUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + appid + "&secret=" + secret;
                //移除拼接過程中產生的換行符、空格
                tokenUrl = tokenUrl.Replace("\n", "").Replace(" ", "").Replace("\t", "").Replace("\r", "");
                string jsonresult = HttpGet(tokenUrl, "UTF-8");
                WX_Token wx = JsonDeserialize<WX_Token>(jsonresult);
                //重新整理資料庫快取資料
                token = wx.access_token;
                //Utils.WriteLog("", "token", "token第二次獲取結果：" + token + "---" + System.DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
            }
            //微信jsapi_ticket  
            string ticket = GetTicket(token);
            if (string.IsNullOrWhiteSpace(ticket))
            {
                 //--------------------------------第二次獲取證書失效，可能是token過期
                string ticketUrl = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + token + "&type=jsapi";

                //移除拼接過程中產生的換行符、空格
                ticketUrl = ticketUrl.Replace("\n", "").Replace(" ", "").Replace("\t", "").Replace("\r", "");
                string jsonresult = HttpGet(ticketUrl, "UTF-8");
                WX_Ticket wxTicket = JsonDeserialize<WX_Ticket>(jsonresult);
                ticket = wxTicket.ticket;
                }
            //當前網頁的URL  
            string pageurl = Request.Url.AbsoluteUri;
            //對所有待簽名引數按照欄位名的ASCII 碼從小到大排序（字典序）後，使用URL鍵值對的格式（即key1=value1&key2=value2…）拼接成字串  
            string str = "jsapi_ticket=" + ticket + "&noncestr=" + nonceStr + "&timestamp=" + timestamp + "&url=" + pageurl;
            //簽名,使用SHA1生成  
            string signature = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "SHA1").ToLower();

            //要註冊到頁面的JS指令碼  
            StringBuilder sbjsApi = new StringBuilder();
            sbjsApi.Append("<script>");

            //通過config介面注入許可權驗證配置  
            sbjsApi.Append("wx.config({debug:false,");
            sbjsApi.Append("appId: '" + appid + "',");
            sbjsApi.Append("timestamp: " + timestamp + ",");
            sbjsApi.Append("nonceStr: '" + nonceStr + "',");
            sbjsApi.Append("signature: '" + signature + "',");
            sbjsApi.Append("jsApiList: ['onMenuShareTimeline', 'onMenuShareAppMessage', 'chooseImage', 'uploadImage', 'getNetworkType']});");
            //通過ready介面處理成功驗證  
            sbjsApi.Append("wx.ready(on_weixin_ready);");
            sbjsApi.Append("function on_weixin_ready() {weixin_share();}");
            //獲取“分享給朋友”按鈕點選狀態及自定義分享內容介面  
            sbjsApi.Append("function weixin_share(){");
            sbjsApi.Append("wx.onMenuShareAppMessage({");
            sbjsApi.Append("title:'" + act_detail_title + "',");
            sbjsApi.Append("desc:'" + act_detail_desc + "',");
            //sbjsApi.Append("link:'分享出去的連結地址',");
            sbjsApi.Append("imgUrl:'" + act_detail_img + "',");
            sbjsApi.Append("type:'link',");
            sbjsApi.Append("dataUrl:'',");
            sbjsApi.Append("success: function () { $.post('../programs/Pro_User.ashx', { action: 'AddShareNo',typeId:'" + SjuneRequest.GetQueryString("id") + "' }, '', 'Json');alert('分享成功！【朋友】');},");
            sbjsApi.Append("cancel:function () {}");
            sbjsApi.Append("});");

            //獲取“分享到朋友圈”按鈕點選狀態及自定義分享內容介面  
            sbjsApi.Append("wx.onMenuShareTimeline({");
            sbjsApi.Append("title:'" + act_detail_title + "',");
            sbjsApi.Append("imgUrl:'" + act_detail_img + "',");
            sbjsApi.Append("success: function () { $.post('../programs/Pro_User.ashx', { action: 'AddShareNo',typeId:'" + SjuneRequest.GetQueryString("id") + "' }, '', 'Json');alert('分享成功！【朋友圈】');},");
            sbjsApi.Append("cancel:function () {}");
            sbjsApi.Append("});}");

            sbjsApi.Append("</script>");

            Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "weixin", sbjsApi.ToString().Trim());
        }

        /// <summary>  
        /// 獲取微信jsapi_ticket  
        /// </summary>  
        /// <param name="token">access_token</param>  
        /// <returns>jsapi_ticket</returns>  
        public string GetTicket(string token)
        {
            string tickId = "";
            //DataSet ds = new BLL.Ticket().GetList(" id=1");
            //int start_time = ds.Tables[0].Rows[0]["Ticket_Dt"].ToInt();
            //int new_time = CreateTimeStamp();
            //if ((new_time.ToInt() - start_time.ToInt()) > 7000)
            //{
            //超時，重新生成並更新資料
            string ticketUrl = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + token + "&type=jsapi";
            ticketUrl = ticketUrl.Replace("\n", "").Replace(" ", "").Replace("\t", "").Replace("\r", "");
            string jsonresult = HttpGet(ticketUrl, "UTF-8");
            WX_Ticket wxTicket = JsonDeserialize<WX_Ticket>(jsonresult);
            //重新整理資料庫快取資料
            //Model.Ticket db_model = new BLL.Ticket().GetModel(1);
            //db_model.Ticket_Dt = CreateTimeStamp().ToString();
            //db_model.Ticket_Id = wxTicket.ticket;
            //new BLL.Ticket().Update(db_model);
            tickId = wxTicket.ticket;
            //}
            //else
            //{
            //    tickId = ds.Tables[0].Rows[0]["Ticket_Id"].ToString();
            //}
            return tickId;
        }

        /// <summary>  
        /// 獲取微信access_token  
        /// </summary>  
        /// <param name="appid">公眾號的應用ID</param>  
        /// <param name="secret">公眾號的應用金鑰</param>  
        /// <returns>access_token</returns>  
        private string GetAccess_token(string appid, string secret)
        {

            string tokenId = "";
            DataSet ds = new BLL.Ticket().GetList(" id=1");
            int start_time = ds.Tables[0].Rows[0]["Ticket_Dt"].ToInt();
            int new_time = CreateTimeStamp();
            if ((new_time.ToInt() - start_time.ToInt()) > 5000)
            {
                //超時，重新生成並更新資料
                string tokenUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + appid + "&secret=" + secret;
                tokenUrl = tokenUrl.Replace("\n", "").Replace(" ", "").Replace("\t", "").Replace("\r", "");
                string jsonresult = HttpGet(tokenUrl, "UTF-8");
                WX_Token wx = JsonDeserialize<WX_Token>(jsonresult);
                //重新整理資料庫快取資料
                Model.Ticket db_model = new BLL.Ticket().GetModel(1);
                db_model.Ticket_Dt = CreateTimeStamp().ToString();
                db_model.Token_Id = wx.access_token;
                new BLL.Ticket().Update(db_model);

                tokenId = wx.access_token;
            }
            else
            {
                tokenId = ds.Tables[0].Rows[0]["Token_Id"].ToString();
            }
            return tokenId;
        }

        /// <summary>  
        /// JSON反序列化  
        /// </summary>  
        /// <typeparam name="T">實體類</typeparam>  
        /// <param name="jsonString">JSON</param>  
        /// <returns>實體類</returns>  
        private T JsonDeserialize<T>(string jsonString)
        {
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
            T obj = (T)ser.ReadObject(ms);
            return obj;
        }

        /// <summary>  
        /// HttpGET請求  
        /// </summary>  
        /// <param name="url">請求地址</param>  
        /// <param name="encode">編碼方式：GB2312/UTF-8</param>  
        /// <returns>字串</returns>  
        private string HttpGet(string url, string encode)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";
            request.ContentType = "application/json; encoding=utf-8";
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding(encode));
            string retString = myStreamReader.ReadToEnd();
            myStreamReader.Close();
            myResponseStream.Close();

            return retString;
        }

        /// <summary>
        /// 生成時間戳
        /// </summary>
        /// <returns></returns>
        private int CreateTimeStamp()
        {
            TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
            return Convert.ToInt64(ts.TotalSeconds).ToInt();
        }

        /// <summary>  
        /// 通過微信API獲取access_token得到的JSON反序列化後的實體  
        /// </summary>  
        public class WX_Token
        {
            public string access_token { get; set; }
            public string expires_in { get; set; }
        }

        /// <summary>  
        /// 通過微信API獲取jsapi_ticket得到的JSON反序列化後的實體  
        /// </summary>  
        public class WX_Ticket
        {
            public string errcode { get; set; }
            public string errmsg { get; set; }
            public string ticket { get; set; }
            public string expires_in { get; set; }
        }

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