private void btnLoaiGia_Click(object sender, RoutedEventArgs e) { if (ucLoaiGia == null) { ucLoaiGia = new UserControlLibrary.UCLoaiGia(mTransit); } spNoiDung.Children.Clear(); ucLoaiGia.Height = spNoiDung.ActualHeight; ucLoaiGia.Width = spNoiDung.ActualWidth; spNoiDung.Children.Add(ucLoaiGia); }