Draw a grid on a TPaintBox

Problem/Question/Abstract:

How to draw a grid on a TPaintBox

Answer:

procedure TForm1.DrawPaintBoxGrid(distance: Integer);
var
  xpos, ypos: Integer;
begin
  PaintBox1.Canvas.Brush.Color := clBlack;
  ypos := 0;
  xpos := 0;
  while ypos < PaintBox1.Height do
  begin
    ypos := ypos + distance;
    PaintBox1.Canvas.MoveTo(0, ypos);
    PaintBox1.Canvas.LineTo(PaintBox1.Width, ypos);
    while xpos < PaintBox1.Width do
    begin
      xpos := xpos + distance;
      PaintBox1.Canvas.MoveTo(xpos, 0);
      PaintBox1.Canvas.LineTo(xpos, PaintBox1.Height);
    end;
  end;
end;