TDBGrid: scroll contents as thumb button is moved?

Question

Is there a way to move the contents of the TDBGrid as you drag the vertical scrollbar thumb button (instead of only moving the contents once released)?

I found something called ScrollTrack property for a DBGrid but I guess that is .Net? Is there something like that for Delphi/C++Builder? Or a way to have it scroll the contents as the thumb button is dragged?

TIA!!

Answer 1

You can do this with an Interposer Class.

Create a new unit with this content:

unit DBGridHelper;

interface

uses
  Winapi.Messages, Winapi.Windows,
  Vcl.DBGrids;

type
  TDBGrid = class(Vcl.DBGrids.TDBGrid)
  private
    procedure WMVScroll(var Message: TWMVScroll); message WM_VSCROLL;
  end;

implementation

procedure TDBGrid.WMVScroll(var Message: TWMVScroll);
begin
  inherited;
  if not (Focused or (InplaceEditor <> nil) and InplaceEditor.Focused) then Exit;
  if Datalink.Active then begin
    case Message.ScrollCode of
      SB_THUMBTRACK: DataLink.DataSet.RecNo := Message.Pos;
    end;
  end;
end;

end.

In each unit containing a TDBGrid that should have this behavior, you need to add this unit to the interface uses clause somewhere after Vcl.DBGrids.