Multiple rows are being marked as selected when selection mode is single

1 Answer 20 Views
Grid
Harold
Top achievements
Rank 1
Harold asked on 12 May 2022, 01:13 AM

I have a grid defined with SelectionMode="GridSelectionMode.Single".  I'm handling the SelectedItemsChanged event and when returning the previously selected row is selected with the newly selected row.  This appears to be happening when an async call to a web api using http client is made.  If I comment out the http call the selection works as expected.

Can someone explain why the http client call could be impacting the selection functionality or how I may go about debugging this?


	

<div ><div ><label for="label">Labels</label><div ><TelerikGrid Data="@Labels" FilterMode="@GridFilterMode.FilterRow" ScrollMode="GridScrollMode.Scrollable" SelectionMode="GridSelectionMode.Single" SelectedItems="@SelectedLabels" SelectedItemsChanged="@((IEnumerable<LabelDto> labelList) => OnSelectAsync(labelList))" Height="200px"><GridColumns><GridColumn Field="@(nameof(LabelDto.Name))"></GridColumn></GridColumns></TelerikGrid></div></div></div> public partial class LabelSelection { private ObservableCollection<LabelDto>? _labels; private int? _selectedValue; public IEnumerable<LabelDto> SelectedLabels { get; set; } = Enumerable.Empty<LabelDto>(); protected async Task OnSelectAsync(IEnumerable<LabelDto> labels) { var l = labels.ToList(); SelectedLabels = l; if (l.Any()) await LabelChangedAsync(l[0]); StateHasChanged(); } ... } public async Task LabelChangeHandlerAsync(LabelDto label) { _currentLabel = label; var labelWithAttributes = await LabelRepo.GetLabelAsync((int)label.Id); //LabelAttributeList.Clear(); //if (labelWithAttributes.Attributes.Any()) //{ // LabelAttributeList.AddRange(labelWithAttributes.Attributes); //} }

 

        public async Task<LabelWithAttributesDto> GetLabelAsync(int id)
        {
            var req = $"labels/{id}?includeAttributes=true";

            _logger.Log(LogLevel.Warning, $"GetLabelsAsync({_client.BaseAddress}{req})...");

// The next call will cause multiple rows to be selected. Commenting this out will make the selections work.
           var apiResponse = await _client.GetStreamAsync(req);
//_logger.Log(LogLevel.Warning, $"...back from GetLabelsAsync({_client.BaseAddress}{req})");

//var label = await JsonSerializer.DeserializeAsync<LabelWithAttributesDto>
//    (apiResponse, new JsonSerializerOptions() { PropertyNameCaseInsensitive = true });

//return label;
return new LabelWithAttributesDto(1, "new", "filename", "100", new List<LabelAttributeDto>());
        }


1 Answer, 1 is accepted

Sort by
0
Marin Bratanov
Telerik team
answered on 15 May 2022, 08:12 AM

Hello Harold,

Does using a synchronous handler for SelectedItemsChanged help? It is not designed for async operations and if you need that, I suggest you use the OnRowClick event, as advised here.

Regards,
Marin Bratanov
Progress Telerik

Love the Telerik and Kendo UI products and believe more people should try them? Invite a fellow developer to become a Progress customer and each of you can get a $50 Amazon gift voucher.

Harold
Top achievements
Rank 1
commented on 16 May 2022, 01:12 AM

How can I determine which event/methods support ASYNC and which do not?

 

Marin Bratanov
Telerik team
commented on 16 May 2022, 06:01 AM

Most do, if there is something specific, the documentation should note it.
Harold
Top achievements
Rank 1
commented on 16 May 2022, 03:16 PM

The documentation online for the Grid does not say anything about not supporting ASYNC.

Telerik UI for Blazor : Grid : SelectedItemsChange

Marin Bratanov
Telerik team
commented on 17 May 2022, 07:41 PM

It links to examples that link the row click event and the code explains that for async operations the row click should be used. 

As a general principle, the <ParameterName>Changed events are often there for parameter binding and not really for long slow operations.

Tags
Grid
Asked by
Harold
Top achievements
Rank 1
Answers by
Marin Bratanov
Telerik team
Share this question
or