How to auto extend a column to fill the available space in the WinForms GridGroupingControl?

Handle QueryColWidth event

To dynamically change the column widths, you have to handle the Grid's QueryColWidth event. The following example shows how you can have the right-most or the left-most column grow to fill the Grid's client area as the Grid size changes.

//Defines the columns to fill the space in the table.
void TableModel_QueryColWidth(object sender, GridRowColSizeEventArgs e)
{
   switch (_colSizeBehavior)
   {
       case colSizeBehavior.RightColumn:
               if(e.Index == this.gridGroupingControl1.TableDescriptor.VisibleColumns.Count)
               {
                  e.Size = this.gridGroupingControl1.ClientSize.Width - this.gridGroupingControl1.TableModel.ColWidths.GetTotal(0,
                  this.gridGroupingControl1.TableDescriptor.VisibleColumns.Count - 1);
                  e.Handled = true;
               }
               break;
       case colSizeBehavior.LeftColumn:
               if(e.Index == this.gridGroupingControl1.TableModel.Cols.FrozenCount + 1)
               {
                  int leftPiece = this.gridGroupingControl1.TableModel.ColWidths.GetTotal(0, this.gridGroupingControl1.TableModel.Cols.FrozenCount);
                  int rightPiece = this.gridGroupingControl1.TableModel.ColWidths.GetTotal(this.gridGroupingControl1.TableModel.Cols.FrozenCount + 2, this.gridGroupingControl1.TableModel.ColCount);
                  e.Size = this.gridGroupingControl1.ClientSize.Width - leftPiece - rightPiece;
                  e.Handled = true;
               }
               break;
       default:
               break;
    }
}

'Defines the columns to fill the space in the table.
Private Sub TableModel_QueryColWidth(ByVal sender As Object, ByVal e As GridRowColSizeEventArgs)
   Select Case _colSizeBehavior
       Case colSizeBehavior.RightColumn
                If e.Index = Me.gridGroupingControl1.TableDescriptor.VisibleColumns.Count Then
                   e.Size = Me.gridGroupingControl1.ClientSize.Width - Me.gridGroupingControl1.TableModel.ColWidths.GetTotal(0, Me.gridGroupingControl1.TableDescriptor.VisibleColumns.Count - 1)
                   e.Handled = True
                End If
       Case colSizeBehavior.LeftColumn
                If e.Index = Me.gridGroupingControl1.TableModel.Cols.FrozenCount + 1 Then
                   Dim leftPiece As Integer = Me.gridGroupingControl1.TableModel.ColWidths.GetTotal(0, Me.gridGroupingControl1.TableModel.Cols.FrozenCount)
                   Dim rightPiece As Integer = Me.gridGroupingControl1.TableModel.ColWidths.GetTotal(Me.gridGroupingControl1.TableModel.Cols.FrozenCount + 2, Me.gridGroupingControl1.TableModel.ColCount)
                   e.Size = Me.gridGroupingControl1.ClientSize.Width - leftPiece - rightPiece
                   e.Handled = True
                End If
       Case Else
   End Select
End Sub