How to show DBGrid.Hint when hovering with the mouse on a cell?

Question

While the following code does correctly set the Form1.Caption with the text of the cell the mouse is over, it does not display any DBGrid.Hint unless I click on the cell.

What is wrong with this picture?

type
 THackGrid = class(TDBGrid); // to expose protected DataLink property

procedure TForm1.DBGrid1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
var
  Cell: TGridCoord;
  ActRec: Integer;
begin
  Cell := DBGrid1.MouseCoord(X, Y);
  if dgIndicator in DBGrid1.Options then
    Dec(Cell.X);
  if dgTitles in DBGrid1.Options then
    Dec(Cell.Y);
  if THackGrid(DBGrid1).DataLink.Active and (Cell.X >= 0) and
    (Cell.Y >= 0) then
  begin
    ActRec := THackGrid(DBGrid1).DataLink.ActiveRecord;
    try
      THackGrid(DBGrid1).DataLink.ActiveRecord := Cell.Y;
      Caption := DBGrid1.Columns[Cell.X].Field.AsString;     // Form1.Caption shows fine!
      DBGrid.Hint := DBGrid1.Columns[Cell.X].Field.AsString; // <== Hint only shows when I click into the cell!
    finally
      THackGrid(DBGrid1).DataLink.ActiveRecord := ActRec;
    end;
  end;
end;

Answer 1

Call Application.ActivateHint with the desired coordinates for the hint, e.g.

Procedure ChangeHint(C: TControl; Const Hint: String; p: TPoint);
var
  OldHint: String;
begin
  OldHint := C.Hint;
  if Hint <> OldHint then
  begin
    C.Hint := Hint;
    Application.ActivateHint(p);
  end;
end;

procedure TForm3.DBGrid1MouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
  ...
  ChangeHint(TDBGrid(Sender), YourIntendedHintText, TDBGrid(Sender).ClientToScreen(Point(X, Y)));
  ....
end;