Last Updated: 21 Jun 2024 12:00 by ADMIN
Release 2024 Q3 (Aug)

In a filterable Grid, if a column is not bound to a field from the model the Grid uses, it throws with:

Error: System.ArgumentNullException: Value cannot be null. (Parameter 'nullableType')


The issue is reproducible :

  • For `FilterRow` -  on initialization even if the column is not filterable.
  • For `FilterMenu` - on initialization when the column is filterable.




A possible workaround for the time being is to set the FieldType of the column:

Last Updated: 19 Jun 2024 12:51 by ADMIN
Scheduled for 2024 Q3 (Aug)
Created by: Greg
Comments: 14
Category: Grid
Type: Feature Request
My users need to select cells rather than entire rows, as they come from an MS Access background.
Last Updated: 17 Jun 2024 08:20 by Max
In the csproj of my application, I have enabled support for nullable reference types (<Nullable>enable</Nullable>). If the filter operator is IsEqualTo the filtering will not match any items. 
Last Updated: 14 Jun 2024 06:58 by Nazim
Currently, changing the DateTime format is possible for all other types of FilterMenus. However, the FilterEditorFormat parameter does not affect the dates in a FilterMenu of type CheckBoxList.
Last Updated: 12 Jun 2024 13:49 by ADMIN
Release 2024 Q3 (Aug)

I have a Grid using checkbox selection and when I un-check a row, the SelectedItemsChanged event is not firing. I'm using an async handler.

The problem appears to happen when a row is selected and then un-selected. The event is firing when it is selected but is not firing when it is un-selected.

<TelerikGrid Data="strategicLevelItems" SelectedItems="selectedStrategic" Width="100%" Height="500px"
                                 ScrollMode="GridScrollMode.Scrollable" SelectionMode="GridSelectionMode.Multiple"
                                 SelectedItemsChanged="@((IEnumerable<GetNavigationNodesModel> strategicItems) => OnStrategicSelectAsync(strategicItems))"
                            <GridCheckboxColumn SelectAll="true" Width="40px" OnCellRender="@GridHelpers.CenterAlign" />
                            <GridColumn Field="@(nameof(GetNavigationNodesModel.Name))" />

    private async Task OnStrategicSelectAsync(IEnumerable<GetNavigationNodesModel> selectedItems)
        selectedStrategic = selectedItems;

        var state = tacticalGrid.GetState();

        var compositeFilter = new CompositeFilterDescriptor() { LogicalOperator = FilterCompositionLogicalOperator.Or };
        foreach (var item in selectedItems)
            compositeFilter.FilterDescriptors.Add(new FilterDescriptor()
                Member = "ParentId",
                Operator = FilterOperator.IsEqualTo,
                Value = item.Id


        await tacticalGrid.SetState(state);

Last Updated: 12 Jun 2024 11:29 by ADMIN
Release 2.18.0

Please add an attribute to Blazor GridColumn which allows to easily format data with the default .NET standard formats

e.g. <GridColumn Field="@(nameof(Item.Price))" Title="Price" Format="0#.##" />

It's a little bit annoying always having to define a template for this purpose.


Not Logged in

Last Updated: 12 Jun 2024 10:51 by ADMIN
Release 2024 Q3 (Aug)

Reproduceable example:

Steps to reproduce:

  • Add a TelerikGrid to the page - most properties on the grid do not matter for this issue
  • Implement the OnStateInit event
  • Define the GridAggregates render fragment within the TelerikGrid, but leave it empty - do not put any components inside it
  • When the page initializes, note that OnStateInit is never fired

If you remove the GridAggregates emtpy render fragment, or put at least one GridAggregate component in it, OnStateInit fires like expected.

In my project, I've created a component that wraps around the TelerikGrid that I use on all my pages, so that I can have many properties and functions set to reasonable defaults for my use case. My component has an option to conditionally include GridAggregate components within the inner TelerikGrid's GridAggregates render fragment based on separate configuration. If no separate configuration is provided, no GridAggregate components are included, and the GridAggregates render fragment is left blank. Since my component is built in razor markup, there isn't a great option for nulling out that render fragment if it's empty. I had no problems with this exact same code in UI for Blazor version 5.1, and I hope this can be fixed.

Last Updated: 12 Jun 2024 10:28 by Jennifer

The Grid will cancel the insertion of a new item when:

  • the new item is not saved yet
  • the new item is expanded and its DetailTemplate is visible
  • the user changes the value of a column that has an editor template

Blazor REPL test page


In the meantime, a possible workaround is to hide the expand button for items, which are not added to the "permanent" Grid data yet. Here is how to do it with CSS:

.k-grid-add-row .k-hierarchy-cell .k-icon {
    display: none;
Last Updated: 12 Jun 2024 07:06 by ADMIN
Created by: Terrence
Comments: 1
Category: Grid
Type: Feature Request
Hi Telerik,

We would like to request for a future improvement, to be able to drag when there is already 1 entry in the Grid. As of now we are able to make a workaround for an empty Grid using the following link: Blazor Grid Row Drag and Drop - Telerik UI for Blazor

We are able to use <NoDataTemplate> and added a padding for it. However, we are unable to do a workaround if there's already 1 entry. See attached "gif".

Thank you.


Last Updated: 07 Jun 2024 10:23 by Constantinos Petridis
There are instances where numeric values from parameters are translated to string. One good example is the RowHeight parameter in the Grid. Make sure to use invariant culture to make sure that the string conversion will work for all cultures with different decimal separators. 
Last Updated: 06 Jun 2024 08:11 by Markus

Until version 6.0 it was possible to set the Grid PageSize to "All" by setting it to the total item count. This workaround no longer works.

Please enhance the API to allow setting an "All" page size with code or initially.

Last Updated: 05 Jun 2024 15:31 by Sukesh
When scrolling up in a virtual Grid, the rows "above" are not be kept or loaded like when scrolling down, and it takes a while before they get loaded and shown. This behaviour is not very user friendly and should be corrected.
Last Updated: 04 Jun 2024 09:42 by ADMIN
Release 2024 Q3 (Aug)
Since Telerik UI for Blazor 6.0.0 if I have defined aggregates and I load the Grid's data with async method the data never loads in the Grid. 
Last Updated: 31 May 2024 10:20 by ADMIN


 documentation missing one extremely "silent" breaking change in grid data binding.

When binding/refreshing(subsequent reload) data to VARIABLE, there is "random" need to call grid.Rebind(); Mostly, when data are loaded outside of the grid, ie by some button, or another component. Used together with selected items and grouping enabled.

<TelerikGrid Data="@GridData" SelectionMode="GridSelectionMode.Single" SelectedItems="..."
						 OnRowClick="@...r"  @ref="GHL" ....>


prior v6.0, everything is OK:

protected async Task ReloadGrid(int? xid)

GridData= await LoadDatafromservice<TItem>...;


After upgrading same code, it silently not displaying data or cras.

new breaking behavior at v6.0  - hotfix, but "ugly one":

protected async Task ReloadGrid(int? xid)

GridData= await LoadDatafromservice<TItem>...;

GHL.Rebind(); //required, otherwise grid content(rows) is not update. Later the grid crash when selecting row etc. Old "rows" are still displayed;


Its weird to gues, where rebind is needed and where not. Previous versions acting as expected(async - task = no problem).
Make it documented, "what is correct" and when.

Or if it is a bug, please move it out from feature request.


Last Updated: 31 May 2024 07:32 by Lance
When you have a Navigable Grid with a Material theme, the sorting on each click does not work. You have to click outside of the header and click again in it to sort. The behavior can be seen only in version 6.0.0.
Last Updated: 28 May 2024 05:59 by ADMIN
Release 2023.2
Created by: Constantinos Petridis
Comments: 2
Category: Grid
Type: Bug Report

When you combine frozen column with row selection and horizontal scrolling is applied (due to column and grid widths), column content are not hidden under frozen columns when a row is selected, as seen bellow in lines 2,3 and 4.

Checkbox, Product Name & Command columns are frozen. "Quantity per Unit" values are clearly visible behind frozen "Product Name" values. You can find a test scenario here (Telerik REPL for Blazor).

All themes suffer from this issue except Fluent theme. With default and bootstrap themes it happens on all odd selected lines and with material theme it happens on all selected lines.

Last Updated: 22 May 2024 16:23 by Anthony
Created by: Anthony
Comments: 0
Category: Grid
Type: Feature Request

Could there be an option to NOT close the filter dropdown when the clear button is pressed? Is there an AutoClose parameter or something else?

I just got a request for this, and their thought is they will have a filter set, then want to click clear, and then still pick new items to filter before leaving the dropdown.

Also, watching it on a touch device made it especially painful.
Last Updated: 22 May 2024 13:00 by Nate

In this example.  Select a cell in column C.  Then double click on another cell in column C.  The unhandled exception will show up and a null reference exception is logged in the console.

The exception message is:

System.InvalidOperationException: TelerikValidationComponent requires a cascading parameter of type EditContext. You can use Telerik.Blazor.Components.TelerikValidationTooltip`1[System.String] inside a EditForm or TelerikForm.

Last Updated: 21 May 2024 15:31 by ADMIN


 when using SetStateAsync(), OnRead is called ok, but loading indicator is not presented as usual.

How to reproduce:

1. button = loading data by SetStateAsync(), no progress indicated.

2. button = loading data throught rebind, is ok

demo in repl

demo is based on

Expected: same behavior as by button 2.  -> Rebind()->OnRead()...loading progress


Last Updated: 17 May 2024 13:11 by ADMIN
Release 2024 Q2 (May)
Subject says it all.  Would like the ability to selectively enable/disable a single checkbox in a checkbox column.
1 2 3 4 5 6