微信获取jsapi_ticket 然后在计算出signature

 最近做微信公众号，记录一下，仅供参看。

关于jsapi_ticket微信公众号有相关说明：

生成签名之前必须先了解一下jsapi_ticket，jsapi_ticket是公众号用于调用微信JS接口的临时票据。正常情况下，jsapi_ticket的有效期为7200秒，通过access_token来获取。由于获取jsapi_ticket的api调用次数非常有限，频繁刷新jsapi_ticket会导致api调用受限，影响自身业务，开发者必须在自己的服务全局缓存jsapi_ticket 。 

Ticket

1 public class Ticket
2  {
3      public string Value { get; set; }
4      public DateTime Time { get; set; }
5  }

WeixinServer

 1        #region 静态全局变量
 2         private static Token _Token = null;
 3         private static Ticket _Ticket = null;
 4         private readonly static string appid = "wx123456789000";
 5         private readonly static string secret = "abcdefghijklmnopqrstuvwxyz";
 6         private readonly static string domain = "http://wechat.mydomain.com";
 7        #endregion

        public string GetTicket()
        {
            bool first = false;
            if (_Ticket == null)
            {
                _Ticket = new Ticket();
                first = true;
            }
            TimeSpan ts = DateTime.Now - _Ticket.Time;
            if (ts.Minutes > 30 || first)
            {
                string access_token = AccessToken();
                string url1 = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=" + access_token + "&type=jsapi";
                string requstStr = HttpHelper.Get(url1);
                string ticket = GetParameter("ticket", requstStr);
                _Ticket.Value = ticket;
                _Ticket.Time = DateTime.Now;
            }
            return _Ticket.Value;
        }

        //获取jssdk所需签名
        public string Signature(string url)
        {
            string noncestr = "Wm3WZYTPz0wzccnW";
            int timestamp = 1414587457;
            string ticket = GetTicket();

            string string1 = "jsapi_ticket=" + ticket + "&noncestr=" + noncestr + "&timestamp=" + timestamp + "&url=" + url;
            string signature = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(string1, "SHA1");
            return signature;
        }