C#实现微信公众号群发消息（解决一天只能发一次的限制）

//执行登陆操作
    public static bool ExecLogin(string name,string pass)
    {
        bool result = false;
        string password = GetMd5Str32(pass).ToUpper();
        string padata = "username=" + name + "&pwd=" + password + "&imgcode=&f=json";
        string url = "http://mp.weixin.qq.com/cgi-bin/login?lang=zh_CN ";//请求登录的URL
        try
        {
            CookieContainer cc = new CookieContainer();//接收缓存
            byte[] byteArray = Encoding.UTF8.GetBytes(padata); // 转化
            HttpWebRequest webRequest2 = (HttpWebRequest)WebRequest.Create(url);  //新建一个WebRequest对象用来请求或者响应url
            webRequest2.CookieContainer = cc;                                      //保存cookie 
            webRequest2.Method = "POST";                                          //请求方式是POST
            webRequest2.ContentType = "application/x-www-form-urlencoded";       //请求的内容格式为application/x-www-form-urlencoded
            webRequest2.ContentLength = byteArray.Length;
            Stream newStream = webRequest2.GetRequestStream();           //返回用于将数据写入 Internet 资源的 Stream。
            // Send the data.
            newStream.Write(byteArray, 0, byteArray.Length);    //写入参数
            newStream.Close();
            HttpWebResponse response2 = (HttpWebResponse)webRequest2.GetResponse();
            StreamReader sr2 = new StreamReader(response2.GetResponseStream(), Encoding.Default);
            string text2 = sr2.ReadToEnd();