Question

I have a Delphi DBGrid that looks normal when it first loads. I have setup an OnTitleClick event that sorts the DBGrid by the column when the title is clicked. As soon as you click on the title, the column title acts like a button being pressed and an ugly black line appears. (See Fig. 2 below)

As soon as the click event is done, the grid looks normal again.

How do you prevent this black line from appearing when you click the column title?

EDIT: QC Submitted to Embarcadero

While turning off the ability to resize columns does make the black line behavior disappear it does take away a very nice feature. I think this behavior needs to be fixed. I have submitted the following QC 98255 to Embarcadero. Please vote for this entry.

UPDATE: 2017-07-30

I found where this horizontal black line is being drawn.
Vcl.Grids > procedure TCustomGrid.DrawMove;

The Canvas.Pen.Width is set to 5. I changed it so the Canvas.Pen.Width := 1;
It looks much so much better. Now when I clicked on the “Contact_Last” title cell the black indicator line is just one pixel wide and much less intrusive.

procedure TCustomGrid.DrawMove;
var
  OldPen: TPen;
  Pos: Integer;
  R: TRect;
begin
  OldPen := TPen.Create;
  try
    with Canvas do
    begin
      OldPen.Assign(Pen);
      try
        Pen.Style := psDot;
        Pen.Mode := pmXor;
        //+----------------------------------------------------------------+
        // Modified 2017-07-30 by Michael J Riley (MJR)
        // Changed Pen.Width from 5 to 1
        // This makes the vertical black move-indicator line 1 pixel wide
        // Which is the same width as column resize vertical line
        //+----------------------------------------------------------------+
        //Pen.Width := 5;
        Pen.Width := 1;
        if FGridState = gsRowMoving then
        begin
          R := CellRect(0, FMovePos);
          if FMovePos > FMoveIndex then
            Pos := R.Bottom else
            Pos := R.Top;
          MoveTo(0, Pos);
          LineTo(ClientWidth, Pos);
        end
        else
        begin
          R := CellRect(FMovePos, 0);
          if FMovePos > FMoveIndex then
            if not UseRightToLeftAlignment then
              Pos := R.Right
            else
              Pos := R.Left
          else
            if not UseRightToLeftAlignment then
              Pos := R.Left
            else
              Pos := R.Right;
          MoveTo(Pos, 0);
          LineTo(Pos, ClientHeight);
        end;
      finally
        Canvas.Pen := OldPen;
      end;
    end;
  finally
    OldPen.Free;
  end;
end;

Answer 1

The black line looks like a column order insert marker.

Try looking for an option that disables column re-ordering.