Thank you for providing additional information. If I understand you correctly you would like to be able to expand all rows, however, when one row is expanded the rest gets collapsed automatically. In this case, you should iterate the GridViewHierarchyRowInfos and collapse all except the current one. You can refer to the following help article: https://docs.telerik.com/devtools/winforms/controls/gridview/hierarchical-grid/how-to/iterating-the-child-rows-collection-of-a-chosen-parent-row-in-hierarchy-radgridview
I prepared an example:
private void RadGridView1_ChildViewExpanded(object sender, ChildViewExpandedEventArgs e)
if (e.ChildViewInfo != null)
foreach (GridViewRowInfo row in radGridView1.Rows)
GridViewHierarchyRowInfo hierarchyRow = row as GridViewHierarchyRowInfo;
if (hierarchyRow != null && hierarchyRow.IsCurrent == false)
hierarchyRow.IsExpanded = false;
Note, this is a sample demonstration. Feel free to modify it in a way to suit your requirements the best.
I hope this helps. If you need further assistance do not hesitate to contact me.
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