Hello,

I’ve run into a reproducible issue with the Blazor Grid in Adaptive mode. After the grid adapts to a smaller container and then the container is expanded again, the data rows scroll while the header remains fixed, so the header and data become detached.

I’m attaching three screenshots that show the sequence:

1. 01.png — Grid in normal (non-adaptive) state.
2. 02.png — After shrinking the container until the grid switches to Adaptive.
3. 03.png — After expanding the container again; scrolling the grid shows the header no longer tracks with the data.

Steps to reproduce

1. Open the REPL I’m providing: [REPL link here].
2. Shrink the container (e.g., resize the pane/window) until the grid switches to Adaptive mode.
3. Expand the container back to a larger width so the grid returns to its standard table view.
4. Scroll the grid using the scrollbar/slider: the body content scrolls, but the header stays static and is no longer aligned with the data.

Expected behavior

Header and data remain synchronized—when the grid is scrolled horizontally/vertically, both header and rows should scroll together.

Actual behavior

After returning from Adaptive to the standard layout, the header does not move with the rows when scrolling; it appears “detached”.

Notes

• I did not add any custom CSS related to header/body layout in the demo.
• I haven’t identified a reliable workaround yet.

Please let me know if this is a known issue, if there’s a fix/workaround, or if you need any additional details.

REPL: https://blazorrepl.telerik.com/cfkXlLFd30pGcc6i09?_gl=1*4qgvh1*_gcl_au*OTEyODU4MzMuMTc1NzU3NDk1Ng..*_ga*MTc1OTQ2OTkzNy4xNzU3NTc0ODY4*_ga_9JSNBCSF54*czE3NTk5OTkxMjgkbzEwJGcxJHQxNzYwMDAxNTkwJGo1MyRsMCRoMA..

A Grid component with GridToolBar increases memory usage due to event handler leaks, specifically associated with the GridToolBar and ColumnMenuToolBar.

I'm using an OnRead grid with ExpandoObjects. The error happens on the backend when trying to process the result of ToDataSourceResult(...)

When trying to access the Items property of AggregateFunctionsGroup in a multi level grouping scenario, using ExpandoObject, and the top level group has a null key, trying to access the Items property will result in a NullReferenceException. I've made this helper, but it cannot process the subgroups because of this error.

private static void FlattenGroup<T>(AggregateFunctionsGroup group, List<T> result)
{
    if (group == null)
    {
        return;
    }

    if (group.HasSubgroups)
    {
        foreach (var sub in group.Items.OfType<AggregateFunctionsGroup>())
        {
            FlattenGroup(sub, result);
        }
    }
    else
    {
        result.AddRange(group.Items.OfType<T>());
    }
}

In a scenario where I have an ExpandoObject with properties A and B, where A = 1 and B = null; grouping by A then B works. Grouping by A or B alone also works. But grouping by B then A causes the NullReferenceException when trying to access the group.Items. 

When Virtual Scrolling is enabled and the grid is set to inline editing, clicking the Add button does not start editing on the first click. The button must be clicked twice for a new row to enter edit mode.

Steps to Reproduce:

1. Open this example - https://blazorrepl.telerik.com/QfaZEibY50abpby200

2. Scroll down the grid.

3. Click the "Add" button.

Upon the first click, a new row is inserted but then immediately closed. You have to click it a second time to insert a new row.

We are experiencing an issue where the ExportToPdfAsync() method on TelerikGrid is returning Excel data (XLSX format) instead of PDF data. This is causing MIME type errors when trying to process the exported data as a PDF.

===ADMIN EDIT===

Workaround

In the meantime, a possible workaround would be to use the document processing library (make sure the correct packages are installed for it) and import the xlsx file to a workbook, and then export the workbook to PDF. Here is an improvised example that demonstrates this by saving the file in your wwwroot folder as a pdf.

@inject IWebHostEnvironment HostingEnvironment

<TelerikGrid Data="@bookList" Height="75svh" Resizable="true" Sortable="true" Pageable="true" PageSize="15"
             FilterMode="@GridFilterMode.FilterMenu" SelectionMode="@GridSelectionMode.Multiple"
             SelectedItems="@SelectedBooks" @ref="@BookGrid"
             SelectedItemsChanged="@((IEnumerable<BookInfo> sel) => OnRowSelect(sel))">
    <GridToolBarTemplate>
        <TelerikButton OnClick="@GenerateReport">Generate PDF</TelerikButton>
    </GridToolBarTemplate>
    <GridExport>
        <GridPdfExport AllPages="true" PageOrientation="GridPdfExportPageOrientation.Landscape"
                       PaperSize="GridPdfExportPaperSize.A3" />
    </GridExport>
    <GridColumns>
        <GridCheckboxColumn CheckBoxOnlySelection="true"></GridCheckboxColumn>
        <GridColumn Field="ISBN">
            <HeaderTemplate><b>ISBN</b></HeaderTemplate>
        </GridColumn>
        <GridColumn Field="Author">
            <HeaderTemplate><b>Author</b></HeaderTemplate>
        </GridColumn>
        <GridColumn Field="Title">
            <HeaderTemplate><b>Title</b></HeaderTemplate>
        </GridColumn>
        <GridColumn Field="Genre">
            <HeaderTemplate><b>Genre</b></HeaderTemplate>
        </GridColumn>
        <GridColumn Field="PublishedYear">
            <HeaderTemplate><b>Year</b></HeaderTemplate>
        </GridColumn>
        <GridColumn Field="CopiesAvailable">
            <HeaderTemplate><b>Copies</b></HeaderTemplate>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

@code {
    private async Task GenerateReport()
    {
        isLoading = true;
        var pdfStream = await BookGrid.ExportToPdfAsync();

        // The stream is actually XLSX, so convert it to PDF
        using var ms = new MemoryStream(pdfStream.ToArray());

        var xlsxProvider = new Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.XlsxFormatProvider();
        var workbook = xlsxProvider.Import(ms);

        var rootPath = HostingEnvironment.WebRootPath;
        var saveLocation = Path.Combine(rootPath, "LibraryBooks.pdf");
        var pdfProvider = new Telerik.Windows.Documents.Spreadsheet.FormatProviders.Pdf.PdfFormatProvider();
        using (var fileStream = new FileStream(saveLocation, FileMode.Create))
        {
            pdfProvider.Export(workbook, fileStream);
        }
    }

    public class BookInfo
    {
        public string ISBN { get; set; }
        public string Author { get; set; }
        public string Title { get; set; }
        public string Genre { get; set; }
        public int PublishedYear { get; set; }
        public int CopiesAvailable { get; set; }
    }

    private List<BookInfo> bookList = new()
    {
        new BookInfo { ISBN = "978-0451524935", Author = "George Orwell", Title = "1984", Genre = "Dystopian", PublishedYear = 1949, CopiesAvailable = 4 },
        new BookInfo { ISBN = "978-0439139601", Author = "J.K. Rowling", Title = "Harry Potter and the Goblet of Fire", Genre = "Fantasy", PublishedYear = 2000, CopiesAvailable = 7 },
        new BookInfo { ISBN = "978-0140449266", Author = "Homer", Title = "The Odyssey", Genre = "Epic Poetry", PublishedYear = -800, CopiesAvailable = 2 }
    };

    private TelerikGrid<BookInfo> BookGrid;
    private List<BookInfo> SelectedBooks = new();
    private bool isLoading = false;

    private void OnRowSelect(IEnumerable<BookInfo> selected)
    {
        SelectedBooks = selected.ToList();
    }
}

Description

Regression introduced in version 10.0.0.

Steps To Reproduce

1. Run this example: https://blazorrepl.telerik.com/GJkCGCvE51aGglud38
2. Filter a Grid column and observe the log below the component.

Actual Behavior

The OnStateChanged event fires 4 times

Expected Behavior

The OnStateChanged event fires 2 times (see https://www.telerik.com/blazor-ui/documentation/components/grid/state#onstatechanged).

Browser

All

Last working version of Telerik UI for Blazor (if regression)

9.1.0

Hy,

It is possible to have default color themes (Primary,Dark,Info,Error,...) for Telerik Blazor Grid component as well without having to change the color by css overriding?

The focus indicator on the GridSearchBox is broken when using an outline themes like A11Y, Bootstrap etc.

Workaround:

Temporarily override the overflow style on .k-toolbar-items (e.g., overflow: unset;) using custom CSS to restore the focus indicator.

Refreshing the Grid data frequently may cause performance issues.

I want to change the default Grid loading animation to a pulsing loader indicator.

When enabling resizing and reordering for the Telerik Grid, using `MinResizableWidth` to set minimal column width will apply the constraint to the column position rather than the actual movable column. This means applying a min width of 200px to the first column will work as expected until the column is moved to another position. Now the column in question no longer has the min width applied, and the column that has moved into the first position has the 200px min width constraint. 

It appears this is due to the constraint being applied to the `data-col-index` rather than the `data-col-initialization-index`, or something to that effect.

The following example has a 200px min-width constraint applied to the "Name" first column, and no custom min-with applied to "Address" second column. Switching the columns by moving the "Name" after the "Address" will apply the constraint to the "Address" and not the "Name".

https://blazorrepl.telerik.com/QJEAcuPE41L7Uhiw44

Currently using 7.1.0 but looks to be an issue in later versions as shown by the REPL example. Tested in Firefox and Chrome.

The column position is arbitrary and the bug isn't due to the constraint being applied to the 0 column, applying the constrain to all even columns then shuffling would result in the constrain still being applied to all even columns.

Hello

The new adaptive toolbar I think doesn't follow the same style as other components, particularly scrollable tabs.

https://demos.telerik.com/blazor-ui/grid/adaptive

The UI scroll buttons shouldn't just disable, they just be hidden/removed from the UI altogether when they are not active (as it is pretty confusing to the user otherwise) - they should only appear when they need to appear. They also take up real-estate for no value.

Telerik already have the same concept in the UI for the scrollable-tabs seen here;

https://demos.telerik.com/blazor-ui/tabstrip/scrollable-tabs

So I see some inconsistency between the 2 UI's and think they should not appear as does on scrollable tabs.

The Grid component creates an invalid property value in its style for the <table> tag like shown below (some of the contents omitted for brevity). Notice the "width: ;" which should have a value in it.

<table style="height: auto; width: ;"></table>

This can be observed for example by creating a page with the below code and the using the browsers developer tools to examine the elements. Both Grids will have their CSS width property be invalid.

<TelerikGrid Data="@data" AutoGenerateColumns="true">
</TelerikGrid>

<TelerikGrid Width="200px" Data="@data" AutoGenerateColumns="true">
</TelerikGrid>

@code {
    private List<Product> data = new () { 
        new Product() {
            Id = 2,
            Name = "Hello product"
        }    
    };

 public class Product {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
    }
}

When attempting to utilize the FilterMenuButtonsTemplate component, after selecting any of the defined action buttons (i.e., Clear, Filter, etc.), the selection will cause the page to refresh.

Steps:

1. Proceed to the Telerik Blazor documentation page for Filter Menu Buttons Template within the Grid component.
2. View the example for Using custom filter menu buttons.
3. Ensure that this is the first time loading the component as the error will only occur on the example page when first initialized.
4. Select the filter button within the “Price” column header.
5. Press the “Clear” button.

If the GridScrollMode.Virtual is enabled for the Grid, and the NoDataTemplate exceeds the height of the Grid container, a user can infinitely scroll inside the table even when there is no data and the template is displaying.

===ADMIN EDIT===

A possible workaround is to apply "overflow-y: hidden;" when the NoDataTemplate is shown: REPL link.