private void btn_Add_Click(object sender, RoutedEventArgs e) { GroupBox groupBox = new GroupBox { Height = 500, Width = 400 }; StackPanel stackPanel = new StackPanel(); TextBlock textBlock = new TextBlock(); TextBox textBox = new TextBox(); groupBox.Header = "Question #1"; groupBox.Style = (Style)groupBox.FindResource("MaterialDesignCardGroupBox"); textBlock.Text = "TextBlock"; textBox.Width = 200; textBox.Height = 30; stackPanel.Children.Add(textBlock); stackPanel.Children.Add(textBox); groupBox.Content = stackPanel; this.grid.Children.Add(groupBox); }