How to resize parent grid columns to automatically adjust child grid columns in WinForms GridGroupingControl?

In WinForms GridGroupingControl, when resizing a parent grid column, the corresponding child grid columns can also be resized based on the parent column width by using the TableModel.ColWidthsChanging event. Within this event, the widths of the nested table columns can be adjusted proportionally to reflect the changes made to the parent column.

//Event subscription
gridGroupingControl1.TableModel.ColWidthsChanging += OnColWidthsChanging;

//Event customization
private void OnColWidthsChanging(object sender, GridRowColSizeChangingEventArgs e)
{
   int col = e.From;
   GridTable table1 = this.gridGroupingControl1.GetTable("ChildTable");
   table1.TableModel.ColWidths[col - 1] = Convert.ToInt32(e.Values.GetValue(0));     
}

Take a moment to peruse the WinForms GridGroupingControl - Columns documentation, to learn more about managing records and columns with examples.