Add graphical bar to a StringGrid col

Question

Using Delphi 2010 and a TStringGrid component, I currently display five filds from a database query.

Here is a simplied example of what i am doing

//set up t

Answer 1

Here you can view a sample (Draw percentage in a cell in a Grid), to draw a bar in a cell of a TStringGrid. The explanation is in spanish, but you can download the code, that is very simple. Also you can use authomatic translation on right of page.

procedure TFormDrawCell.DBGrid1DrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumn;
  State: TGridDrawState);
const
  STR_EMPTY = '';
  CHAR_PERCENT = '%';
  SPACE_TO_CENTER_CELLTEXT = 0;
var
  fValue: Integer;
  ActualPenColor, ActualBrushColor: TColor;
  EmptyDS: Boolean;
  DrawRect: TRect;
  fWidth1, fLeft2: Integer;
  StrValue: string;
begin
  if not (Column.FieldName = 'Precent') then
    Exit;

  if not (cbdraw.Checked) then
    Exit;

  EmptyDS := ((TDBGrid(Sender).DataSource.DataSet.EoF) and
              (TDBGrid(Sender).DataSource.DataSet.Bof));

  if (Column.Field.IsNull) then begin
    fValue := -1;
    StrValue := STR_EMPTY;
  end
  else begin
    fValue := Column.Field.AsInteger;
    StrValue := IntToStr(fValue) + CHAR_PERCENT;
  end;

  DrawRect := Rect;
  InflateRect(DrawRect, -1, -1);

  fWidth1 := (((DrawRect.Right - DrawRect.Left) * fValue) DIV 100);

  ActualPenColor := TDBGrid(Sender).Canvas.Pen.Color;
  ActualBrushColor := TDBGrid(Sender).Canvas.Brush.Color;
  TDBGrid(Sender).Canvas.Pen.Color := clHighlight;
  TDBGrid(Sender).Canvas.Brush.Color := clWhite;
  TDBGrid(Sender).Canvas.Rectangle(DrawRect);

  if (fValue > 0) then begin
    TDBGrid(Sender).Canvas.Pen.Color := clSkyBlue;
    TDBGrid(Sender).Canvas.Brush.Color := clSkyBlue;
    DrawRect.Right := DrawRect.Left + fWidth1;
    InflateRect(DrawRect, -1, -1);
    TDBGrid(Sender).Canvas.Rectangle(DrawRect);
  end;

  if not (EmptyDS) then begin
    DrawRect := Rect;
    InflateRect(DrawRect, -2, -2);
    TDBGrid(Sender).Canvas.Brush.Style := bsClear;
    fLeft2 := DrawRect.Left + (DrawRect.Right - DrawRect.Left) shr 1 -
              (TDBGrid(Sender).Canvas.TextWidth(StrValue) shr 1);
    TDBGrid(Sender).Canvas.TextRect(DrawRect, fLeft2,
                                    DrawRect.Top + SPACE_TO_CENTER_CELLTEXT, StrValue);
  end;

  TDBGrid(Sender).Canvas.Pen.Color := ActualPenColor;
  TDBGrid(Sender).Canvas.Brush.Color := ActualBrushColor;
end;

Regards.