[Solved] Scroll into view the expanded record

[Jingying]

My gridview has childhiereachy, just like the Firstlook example
http://demos.telerik.com/silverlight/#GridView/FirstLook

If you expand a record towards the bottom of the grid, can you "scroll" or "jump" into view.
Ie. i want the expanded record to be visible, ie moved into view

[Rossen Hristov]

Hello Jingying,

Currently that is not possible out of the box. However, we have gone the extra mile and created a custom solution for you. It is a little bit complex and relies on the "internal" parts of the grid to do the job, but we hope that it might help in your case. The idea behind our solution is simple -- when a row is expanded -> scroll it to the ceiling of the viewport. We have attached to the RowLoaded event of the grid and here is what we did:

        void OnRowLoaded(object sender, RowLoadedEventArgs e)
        {
            var expandableRow = e.Row as GridViewExpandableRow;
            if (expandableRow != null)
            {
                expandableRow.ExpanderRowStateChanged += this.OnExpandableRowStateChanged;
            }
        }

        void OnExpandableRowStateChanged(object sender, RoutedEventArgs e)
        {
            GridViewExpandableRow expandableRow = (GridViewExpandableRow)sender;
            if (expandableRow.IsExpanded)
            {
                GridViewVirtualizingPanel vpanel = this.grid.ItemsControl.VirtualizingPanel;
                double offsetY = ((MatrixTransform)expandableRow.TransformToVisual(vpanel)).Matrix.OffsetY;
                vpanel.SetVerticalOffset(vpanel.VerticalOffset + offsetY);
            }
        }

This pushes each row to the top as soon as it is expanded. I have attached the sample project that this code snippet is taken from. I hope it helps.

Best wishes,
Ross
the Telerik team

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[Jingying]

That works. Thanks a lot, really appreciate the great support here.