Example code blocks are sometimes separated into 2 or more blocks

Example code is sometimes separated into 2 blocks, although could be displayed in the single block. This applies to multiple articles and multiple code languages. The publishing system can't merge two snippets into a single presented snippet block in the published article. The original authors tried to reuse portions of code which required them to use more than one code block, one after the other. Frankly, it looks terrible.

This issue is to track which articles have this problem and serve as a jumping off point for contributors to identify where to fix the issue.


### Articles that need to be fixed:

- [ ] [wpf/xaml/index.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/xaml/index.md)
- [ ] [winforms/controls/customize-cells-and-columns-in-the-datagrid-by-extending-behavior.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/winforms/controls/customize-cells-and-columns-in-the-datagrid-by-extending-behavior.md)
- [ ] [wpf/controls/how-to-use-triggers-to-style-selected-items-in-a-listview.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/controls/how-to-use-triggers-to-style-selected-items-in-a-listview.md)
- [ ] [wpf/data/how-to-bind-to-a-collection-and-display-information-based-on-selection.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/data/how-to-bind-to-a-collection-and-display-information-based-on-selection.md)
- [ ] [wpf/data/how-to-set-up-notification-of-binding-updates.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/data/how-to-set-up-notification-of-binding-updates.md)
- [ ] [wpf/data/how-to-specify-the-binding-source.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/data/how-to-specify-the-binding-source.md)
- [ ] [wpf/data/how-to-set-up-notification-of-binding-updates.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/data/how-to-set-up-notification-of-binding-updates.md)
- [ ] [wpf/data/data-templating-overview.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/data/data-templating-overview.md)
- [ ] [wpf/controls/how-to-resize-columns-with-a-gridsplitter.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/controls/how-to-resize-columns-with-a-gridsplitter.md)
- [ ] [wpf/controls/how-to-resize-rows-with-a-gridsplitter.md](https://github.com/dotnet/docs-desktop/blob/main/dotnet-desktop-guide/wpf/controls/how-to-resize-rows-with-a-gridsplitter.md)