/// <summary>
        /// 推送给指定的账号,限iOS系统使用。
        /// </summary>
        /// <param name="accessId"></param>
        /// <param name="secretKey"></param>
        /// <param name="content"></param>
        /// <param name="account"></param>
        /// <param name="env"></param>
        /// <returns></returns>
        public static string pushAccountIos(long accessId, string secretKey,
                                            string content, string account, iOSEnvironment env)
        {
            var message = new MessageIOS();

            message.setAlert(content);
            message.setBadge(1);
            message.setSound(Constants.beep_wav);

            var xinge = new XingeApp(accessId, secretKey);
            var ret   = xinge.PushSingleAccount(account, message, env);

            return(ret);
        }
        /// <summary>
        /// 推送给绑定标签的设备,限iOS系统使用。
        /// </summary>
        /// <param name="accessId"></param>
        /// <param name="secretKey"></param>
        /// <param name="content"></param>
        /// <param name="tag"></param>
        /// <param name="env"></param>
        /// <returns></returns>
        public static string pushTagIos(long accessId, string secretKey,
                                        string content, string tag, iOSEnvironment env)
        {
            var message = new MessageIOS();

            message.setAlert(content);
            message.setBadge(1);
            message.setSound(Constants.beep_wav);

            var xinge   = new XingeApp(accessId, secretKey);
            var tagList = new List <string> {
                tag
            };
            string ret = xinge.PushTags(tagList, OR, message, env);

            return(ret);
        }