procedure TForm1.Button1Click(Sender: TObject);
var
  myRect: TGridRect;
begin
  myRect.Left := -1;
  myRect.Top := -1;
  myRect.Right := -1;
  myRect.Bottom := -1;
  StringGrid1.Selection := myRect;
end;

type
  TForm1 = class(TForm)
    StringGrid1: TStringGrid;
    procedure FormCreate(Sender: TObject);
    procedure StringGrid1Exit(Sender: TObject);
  private
  public
  end;    var
  Form1: TForm1;    implementation    {$R *.DFM}    procedure TForm1.FormCreate(Sender: TObject);
begin
  StringGrid1.Selection := TGridRect(Rect(-1,-1,-1,-1)) ;
end;    procedure TForm1.StringGrid1Exit(Sender: TObject);
begin
  StringGrid1.Selection := TGridRect(Rect(-1,-1,-1,-1)) ;
end;