/// <summary>
        /// OnAfterRenderAsync
        /// </summary>
        /// <param name="firstRender"></param>
        protected override async Task OnAfterRenderAsync(bool firstRender)
        {
            if (firstRender)
            {
                GatewayList = await RegistryHelper.GetGatewayListAsync();

                Page = "1";
                _pagedGatewayList    = GatewayList.GetPaged(int.Parse(Page), CommonHelper.PageLength, GatewayList.Error);
                CommonHelper.Spinner = string.Empty;
                CommonHelper.CheckErrorOrEmpty(_pagedGatewayList, ref _tableView, ref _tableEmpty);
                StateHasChanged();
                _gatewayEvent = await RegistryServiceEvents.SubscribeGatewayEventsAsync(
                    ev => InvokeAsync(() => GatewayEvent(ev)));
            }
        }
 protected override async Task SubscribeEvents()
 {
     _events = await RegistryServiceEvents.SubscribeGatewayEventsAsync(
         ev => InvokeAsync(() => GatewayEvent(ev)));
 }