Réponse acceptée !
procedure TForm1.DBGrid1KeyPress(Sender: TObject; var Key: Char);
begin
if autorise and (not (key in ['0'..'9'])) then key:=#0;end;
procedure TForm1.DBGrid1CellClick(Column: TColumn);
begin
autrorise := column.Field.DataType=Ftinteger;end;
procedure TForm1.FormCreate(Sender: TObject);
begin
autorise:=false;
end;