ASP.NET - Como saber se select Retornou registros

fbConnection1.Open;
  fbCommand1.CommandText := ´Select * from usuarios where usuario_id = 45646546546´;
  Dr := fbCommand1.ExecuteReader;
  if dr.HasRows
  then
  begin
   DR.Read;
   TextBox1.Text := ´tem registros´
  end
  else
  begin
   TextBox1.Text := ´Não tem registros´
  end;