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.

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

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();
    }
}

Similar to the WPF grid I would like the option to require the user hold shift to sort by multiple columns, otherwise the grid would sort by only a single column.

https://docs.telerik.com/devtools/wpf/controls/radgridview/sorting/multiple-column-sorting

In the case of a sorted column, NVDA is not narrating the correct column name and narrating the incorrect Roles for the column headers.

In the case of an unsorted column, NVDA is narrating the column name twice and repeating the information.

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 issue targets a Grid with cell selection and DragToSelect feature disabled where at least one column has Visible="false". With this configuration, when using Shift + Click to select multiple cells, the result is a mismatch in the cells that should be selected, after the position where the invisible column is placed.

Video reproduction attached. Reproduction code: https://blazorrepl.telerik.com/GyFuQwPf37H8riAM19.

After filtering a nullable int column, the SelectAll checkbox in the GridCheckboxColumn stops working.

Reproduction example: https://blazorrepl.telerik.com/mTuyHaYM44sLH2yf05

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.