public async void ExecuteLoadItemsNotifications(object sender, EventArgs e)
 {
     IsBusy = true;
     StartLoading();
     BindingContext = viewModel;
     ItemsListViewiOS.EndRefresh();
     IsBusy = false;
 }
        private async void StartLoading()
        {
            viewModel.VisibleLoad    = true;
            viewModel.LoadingMessage = "";

            bool isSuccess = await GetNotifications();

            viewModel.VisibleLoad = false;
            if (isSuccess)
            {
                viewModel.LoadingMessage = "Success";
            }
            else
            {
                viewModel.VisibleLoad = false;
                Common.Instance.ShowToastMessage("Error communication with server!", DoubleResources.DangerSnackBar);
            }
            ItemsListViewiOS.EndRefresh();
            IsBusy = false;
        }