Professional C# 7 and .NET Core 2.0, 7th Edition

34Patterns with XAML Apps

WHAT’S IN THIS CHAPTER?

• Sharing code
• Creating models
• Creating repositories
• Creating ViewModels
• Navigation between pages
• Adaptive user interfaces
• Using an event aggregator
• List Items with view models

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

The Wrox.com code downloads for this chapter are found at www.wrox.com on the Download Code tab. The source code is also available at https://github.com/ProfessionalCSharp/ProfessionalCSharp7 in the directories Patterns and PatternsXamarinShared. The libraries are shared between Chapter 34 and Chapter 37, “Xamarin.Forms.”

The code for this chapter contains the project BooksApp.

WHY MVVM?

Technologies and frameworks change. I created the first version of my company website (http://www.cninnovation.com) with ASP.NET Web Forms. When ASP.NET MVC came along, I tried it out to migrate a feature of my site to MVC. The progress was a lot faster than I expected. Within one day I transformed the complete site to MVC. The site uses SQL Server, integrates RSS feeds, and shows trainings and books. Information about the trainings and books is coming from the SQL Server database. The fast migration to ASP.NET MVC was only possible because I had separation of concerns from the beginning; I had created separate layers for the data access and business logic. With ASP.NET Web Forms it would have been possible to directly use data source and data controls within the ASPX page. Separating the data access and business logic ...