private void LoadOfflineMessages()
 {
     if (_type == ChatType.Peer)
     {
         var messages = AgoraRtm.GetOfflineMessages(ChannelOrPeerName);
         messages.ForEach(m => AppendMsg(ChannelOrPeerName, m));
         AgoraRtm.RemoveAllOfflineMessages(ChannelOrPeerName);
     }
 }
        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            var dataSource = new TableSource(_messages);

            Table.DataSource = dataSource;
            Table.Delegate   = new TableDelegate(dataSource);
            LoadOfflineMessages();

            _rtmDelegate = new RtmDelegate();
            _rtmDelegate.AppendMessage += AppendMsg;

            AgoraRtm.UpdateKit(_rtmDelegate);
        }