12.0.8 - 2026-10-10

Improvements

• TileLayout gets an AllowOverlap parameter. When it is false a move or resize that would place a tile over another visible tile is blocked: the tile first tries the free axis alone so a diagonal drag slides along the neighbor, otherwise it stays at its last valid cell. Tiles that already overlap when the drag starts are ignored so they can still be pulled apart. The default stays true.

Fixes

• DataGrid keeps expanded rows consistent across Reload when KeyProperty is set. The row toggler icon resolved the expanded state by key while the detail row and CollapseItem resolved it by object reference, so after Reload returned fresh objects with the same keys the icon stayed expanded, the detail disappeared and clicking the icon could not remove the stale entry. The row template now uses IsRowExpanded, CollapseItem removes the stored key that matches by KeyProperty, Single expand mode compares with ItemEquals and the hierarchy view re-keys the child data to the fresh parent object so expanded children survive a reload (#2752).
• AutoComplete keeps Value when it is declared before Data in the markup. Blazor assigns parameters in markup order and the Data setter resets the stored value whenever Data changes, so a Value declared before Data was lost on the first render and again every time Data was replaced. The Value parameter is now captured before the first await and re-applied after the base call when the Data setter has reset it (#2754).
• DataGrid filtering a collection column translates to SQL again when Data is an EF Core IQueryable. The null guard added around Any/All and IsEmpty/IsNotEmpty collection filters protects in-memory data with null collections, but EF Core cannot translate a null comparison of a projected collection such as c.Orders.Select(o => o.Number).ToList() and failed the whole query with "could not be translated". The guard is now emitted only for in-memory sources, so database providers get a plain Any/All as in 11.1.6 (#2755).