delphitvirtualstringtree

TVirtualStringTree, position of the tree structure

The visual tree structure of the VirtualStringTree always sticks to the 1st column (the one with index = 0). When you change columns sequence by dragging a column header the tree may look weird (the image below). Is it possible to have the structure be seen always in the first visible column? Test

Solution

  • The structure is displayed based on the TVirtualStringTree.Header.MainColumn which needs to be changed every time a column is moved, because moving a column doesn't change its index, but the TVirtualTreeColumn.Position property. The easiest way is to use OnHeaderDragged.

    procedure HeaderDragged(Sender: TVTHeader; Column: TColumnIndex; OldPosition: Integer);
begin
  MyTree.Header.MainColumn := MyTree.Header.Columns.ColumnFromPosition(0);
end;