12.0.6 - 2026-10-06

Improvements

• Spreadsheet Worksheet.RightToLeft displays a sheet right to left, with column A on the right. XlsxWriter writes it as rightToLeft="1" on the sheet view and XlsxReader reads it back, so Arabic and Hebrew workbooks no longer open left to right. The RadzenDataGrid Excel export follows the computed direction of the rendered grid, and the new DataGridExcelExportOptions.RightToLeft overrides it (#2748).

Fixes

• Chart panning and zooming stay responsive with large datasets. Dragging the scrollbar, panning by touch, spinning the wheel or pinching sent one interop call per native event, so a short drag over a 20000 item column series queued 60 OnPan calls that each re-rendered every column and took over two minutes to settle. The zoom and pan interop is now serialized, with the newest pan position and the accumulated wheel steps sent in one call, RadzenColumnSeries and RadzenBarSeries skip the items outside the zoomed plot area, and RadzenLineSeries and RadzenAreaSeries build their path from the points that reach it plus the neighbors the curve needs, unless AnimateDataUpdates is set. A zoomed chart with 20000 columns now settles 40 ms after the last scrollbar move (#2749).
• Chart value axis with both Min and Max and no Step always labels Max. The tick step divides the pinned range evenly instead of rounding up to a whole number, which pushed the last tick past Max and dropped it whenever the range was not a multiple of the tick count, for example Min="0" Max="100" ended at 68. Axes with Step, with a single bound or with neither are unchanged.
• Gantt Day and Month zoom headers follow Culture and HeaderDateFormat instead of a hard-coded M/d. The day labels of the Day zoom and the week range labels of the Month zoom use HeaderDateFormat when it is set, and otherwise the short date pattern of the Gantt culture without its year part (M/d for en-US, dd/MM for en-GB, dd.MM for de-DE). The Gantt passes its Culture and UICulture to the inner scheduler, and the zoom buttons carry a class per view (rz-gantt-view-day, -week, -month, -year, -years) so an application can hide a zoom by class instead of by position (#2745).
• Spreadsheet no longer raises "There was an exception invoking 'OnResize'" when it is disposed, for example when a dialog that hosts it closes or the page navigates away. The virtual grid's ResizeObserver fired once more with a 0x0 size for the detached scroll container and called OnResize on an already disposed DotNetObjectReference. The observer now disconnects itself when the scroller is no longer connected, and the call is guarded like the other resize observers (#2746).
• Spreadsheet xlsx export no longer writes applyQuotePrefix on the cell style of a quote-prefixed cell. The attribute is not part of CT_Xf in ECMA-376, so strict readers such as openpyxl refused the file with "unexpected keyword argument 'applyQuotePrefix'". Only quotePrefix="1" is written now (#2747).