delphi – 如何在TVirtualStringTree中填写滚动条上方的区域？

我已经尝试添加额外的列.我已经尝试扩展PainTinfo.PaintRectangle.我已经尝试了我可以想到的amount列中的每个设置.我没有想法

任何人有什么想法如何做到这一点？

这是自定义标题绘图的代码. (原谅与声明,不是我原来的代码….)

procedure TWinPOSReceiptPluginForm.ReceiptDisplayTreeAdvancedHeaderDraw(Sender: TVTHeader; var PainTinfo: THeaderPainTinfo;
  const Elements: THeaderPaintElements);
var
    TempText: String;
begin
    with PainTinfo do
    begin
      // First check the column member. If it is Nocolumn then it's about the header BACkground.

        if (hpeBACkground in Elements) and (column <> nil) then begin
          TempText := column.Text;
          TargetCanvas.brush.Color := $444444;
          TargetCanvas.FillRect(PaintRectanglE);
          TargetCanvas.Font.Color := clWhite;
          TargetCanvas.Font.Style := [];
          TargetCanvas.TextOut (PaintRectangle.Left + 3,PaintRectangle.Top + 3,TempText);
          end;
    end;
end;