TDrawGrid

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TDrawGrid is a component on the Additional tab of the Component Palette. A DrawGrid provides a tabular display of graphical information. The developer is responsible for providing the code for drawing.

Therefore, unlike other grid types, TDrawGrid requires implementing the following properties:

• OnDrawCell(Sender: TObject; aCol, aRow: Integer; aRect: TRect; aState: TGridDrawState): Handler for the basic cell painting event
• DefaultDrawing: a boolean property deciding whether or not OnDrawCell has to handle the entire code for cell painting.

The following simple example shows how to use OnDrawCell:

procedure TForm1.DrawGrid1DrawCell(Sender: TObject; aCol, aRow: Integer;
  aRect: TRect; aState: TGridDrawState);
var
  theCanvas: TCanvas;
  theRect: TRect;
begin
  theCanvas := TDrawGrid(Sender).Canvas;
  if odd(aRow) then
  begin
    if odd(aCol) then
      theCanvas.Brush.Color := clRed
    else
      theCanvas.Brush.Color := clGreen;
  end
  else
  begin
    if odd(aCol) then
      theCanvas.Brush.Color := clBlue
    else
      theCanvas.Brush.Color := clYellow;
  end;
  theCanvas.FillRect(theRect);
end;

The demonstration code in this example fills the content of the cells with different colours, depending on whether the rows or columns are even or odd:

See also

• TStringGrid
• TDBGrid
• Grids Reference Page