delphi : how can I change color of a cell in string grid

Question

I want to change background color ( not font ) of a cell in string grid in delphi .

Just one cell not a row or a column.

Can I?

---

RRUZ : your procedure is correct and works but in my procedure doesn't work.

My procedure:

x is a global array of integer

procedure TF_avalie_salon.StringGrid1DrawCell(Sender: TObject; ACol,
    ARow: Integer; Rect: TRect; State: TGridDrawState);
    var   S: string;
begin
    S := StringGrid1.Cells[ACol, ARow];
    StringGrid1.Canvas.FillRect(Rect);
    SetTextAlign(StringGrid1.Canvas.Handle, TA_CENTER);
    StringGrid1.Canvas.TextRect(Rect,Rect.Left + (Rect.Right - Rect.Left) div 2, Rect.Top + 2, S);
    if (ARow<>0 )AND(acol<>0)AND(gridclick=true) then
    begin
        try
          gridclick:=false;
          x[acol+((strtoint(Edit_hafte.Text)-1)*7),arow]:=strtoint(StringGrid1.Cells[ACol, ARow]);
        except
          x[acol+((strtoint(Edit_hafte.Text)-1)*7),arow]:=0;
          StringGrid1.Cells[acol,arow]:='0';
          with TStringGrid(Sender) do
          begin
            Canvas.Brush.Color := clGreen;
            Canvas.FillRect(Rect);
            Canvas.TextOut(Rect.Left+2,Rect.Top+2,Cells[ACol, ARow]);
          end;
        end;
    end;
end;

---

When I use Canvas.Brush.Color with below code , Canvas.Brush.Color doesn't work. If I inactive below code I can change the cells color. But I need both.

    S := StringGrid1.Cells[ACol, ARow];
    StringGrid1.Canvas.FillRect(Rect);
    SetTextAlign(StringGrid1.Canvas.Handle, TA_CENTER);
    StringGrid1.Canvas.TextRect(Rect,Rect.Left + (Rect.Right - Rect.Left) div 2, Rect.Top + 2, S);

Answer 1

procedure StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;
  Rect: TRect; State: TGridDrawState);
var
i:integer;  
begin
  with Sender as TStringGrid do
    begin
        Canvas.FillRect(Rect);
        DrawText (Canvas.Handle,
            PChar(Cells[ACol, ARow]),
            Length(Cells[ACol, ARow]),
            Rect, DT_WORDBREAK or DT_EXPANDTABS or DT_CENTER);
    end;
    for i:=2 to  StringGrid1.RowCount - 1 do
    if StringGrid1.Cells[3,i]='' then
      begin
        StringGrid1.Canvas.Brush.Color:=clRed;
          if ((ACol=3)and(ARow=i)) then
            begin
              StringGrid1.Canvas.FillRect(Rect);

            end;
      end;


end;

Answer 2

I used these codes, translated to C++. There are two specific notes, then I'll post the code.

1. In "StringGrid1", the property "DefaultDrawing" must be FALSE for this to work.

2. The "Canvas" object must be fully qualified: ie. StringGrid1->Canvas->Font->Color =clBlack.

CODE:

void __fastcall TForm3::StringGrid1DrawCell(TObject *Sender, int ACol, int ARow, TRect &Rect,
      TGridDrawState State)
{
UnicodeString   uStr = "Hello";
int     k, l;
char    cc[100];


if(TRUE)
    {
    if((ACol <= 1) || (ARow <= 1))
        {
        StringGrid1->Canvas->Font->Color = clBlack;
        StringGrid1->Canvas->Brush->Color = clBtnFace;
        if(ACol == 0)
            {
            if(ARow > 1)
                {
                sprintf( cc, " %5.1f", rowLabels[ARow - 2]);
                uStr = cc;
                StringGrid1->Canvas->TextRect( Rect, Rect.left+2, Rect.top+2, uStr);
                StringGrid1->Canvas->FrameRect(Rect);
                }
            }
        if(ARow == 0)
            {
            if(ACol > 1)
                {
                sprintf( cc, " %5.1f", colLabels[ACol - 2]);
                uStr = cc;
                StringGrid1->Canvas->TextRect( Rect, Rect.left+2, Rect.top+2, uStr);
                StringGrid1->Canvas->FrameRect(Rect);
                }
            }
        }
    else
        {
        switch (ACol%2)
            {
            case 0:
                {
                StringGrid1->Canvas->Font->Color = clRed;
                StringGrid1->Canvas->Brush->Color = 0x00E1FFF9;
                break;
                }
            case 1:
                {
                StringGrid1->Canvas->Font->Color = clBlue;
                StringGrid1->Canvas->Brush->Color = 0x00FFEBDF;
                break;
                }
            }
        StringGrid1->Canvas->TextRect( Rect, Rect.left+2, Rect.top+2, uStr);
        StringGrid1->Canvas->FrameRect(Rect);
        }
    }
}

Answer 3

The Rafael link contains all which you need, using the OnDrawCell event is the way to paint the cells of a StrignGrid. check this sample which paint only the background of an specific cell.

procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;  Rect: TRect; State: TGridDrawState);
begin
  if (ACol = 3) and (ARow = 2) then
    with TStringGrid(Sender) do
    begin
      //paint the background Green
      Canvas.Brush.Color := clGreen;
      Canvas.FillRect(Rect);
      Canvas.TextOut(Rect.Left+2,Rect.Top+2,Cells[ACol, ARow]);
    end;
end;