Delphi Tips : Displaying Image in DBGrid Columns

In this tutorial I will share tips about how to displaying image in the DBGrid columns. You can use this method to mark rows that meet certain conditions matching with the conditions you specified. The components which I use is a TDBGrid, a TDatasource, and it is of course a TADOTable which is connected to a table in a Microsoft Access database. Set each of the component properties so that the components is connected to each other.

The following example show how images is used to mark the records base on value on the UnitsInStock column.

condition :

the product which its UnitsInStock value greater or equal to 10 is marked with a checklist image (checklist.bmp) and product which its UnitsInStock less than 10 is marked with a warning image (warning.bmp).

The Code

procedure TForm1.DBGrid1DrawColumnCell
(Sender: TObject; const Rect: TRect;
DataCol: Integer; Column: TColumn;
State: TGridDrawState);

var
  Image : TBitMap;
begin
  Image := TBitmap.Create;

   try
    with Image do begin
      Transparent := True;
      TransParentColor := Image.Canvas.Brush.Color;
      TransparentMode := tmAuto;
    end;

{ Image will only displayed if the table is not empty }
if DataSource1.DataSet.RecNo > 0 then
begin
    if Column.Title.Caption = 'Stock OK' then
    begin
      { if the quantity > 10 }
      if (ADOTable1.FieldValues['unitsinstock'] > 10) then
      begin
      Image.LoadFromFile
      (ExtractFilePath(Application.ExeName)+'\good.bmp');
      DBGrid1.Canvas.Draw(rect.Left + 2,Rect.Top,Image);
      end;

      { if the quantity > 0 and <= 10 }
      if (ADOTable1.FieldValues['unitsinstock'] > 0)
      and (ADOTable1.FieldValues['unitsinstock'] <= 10) then
      begin
      Image.LoadFromFile
      (ExtractFilePath(Application.ExeName)+'\warning.bmp');
      DBGrid1.Canvas.Draw(rect.Left + 2,Rect.Top,Image);
      end;

    end;
end;

  finally
    Image.Free;
  end;

end;

You can download the source code here