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

13
votes

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);
3
delphibackground-colortstringgrid
The code which makes the cell Green is only executed in case of an exception and that is almost only possible in the StrToInt-function. Is that intentional? – Andreas
yeah andreas ,,, i want to change a cell color when it makes a problem . – Arash
admin or modirator : can i ask this question again ( for completing and clearing ) – Arash
This is duplicated, there are many questions reggarding customdraw here in stackoverflow. Painting a cell or a text works the same way. You just need to use the correct property. – Rafael Colucci

3 Answers

11
votes

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;
3
votes

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);
        }
    }
}
0
votes
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;