Summary

At the start of this chapter, you downloaded the latest source for the C# programming language. Then, you restored it, built it, and ran various tests. After that, you built a Hello, World! program that demonstrated C# 9.0 features.

Then, you learned what's new in .NET 5. This section covered topics on garbage collection, JIT compilation, text-based processing, threading and asynchronous operations, collections, LINQ, networking, and Blazor. We also covered the new performance-based APIs and analyzers. From what was covered, you now have a high-level appreciation of the many performance improvements made by Microsoft and third parties to the new version of the .NET programming language. These performance improvements are a solid reason to move to .NET 5. But another compelling reason is also the move to .NET for true cross-platform development from a single code base.

After reviewing the performance improvements and additions to .NET 5, we looked at the new C#10.0 features. You learned how to write a program with just one line of code using top-level statements. Then, you learned how to implement init-only properties, records, new pattern-matching features, new expressions with targeted types, and covariant returns. From reviewing the new additions to the C# 9.0 language, you learned how to compile and run code in MSIL, and then compile and run native code in a single executable file. Visually, the end user experience was shown to be better when using the native binary over the MSIL assembly. For the example, we used a simple audio file format converter.

You were then provided with some guidance on how to improve Windows Store app performance. Links to the official Microsoft documentation were presented to you to help you generate performance reports, along with how to understand the results of the performance assessment. This guidance also highlighted the main metrics to pay attention to. Finally, we considered some ways in which you can improve the performance of your ASP.NET websites and APIs. In the Further reading section, you will find a link to the official Microsoft ASP.NET documentation. This documentation will help you architect and build quality websites.

Furthermore, in the Further reading section, you will find some links to documentation and the GitHub repository for .NET MAUI, which is due to be released in 2021 in concert with .NET 6. This user interface technology is an evolution of Xamarin.Forms with evolutionary changes based on customer research. It does look rather promising.

In the next chapter, we will be looking at .NET interoperability. But before that, work through this chapter's questions to see how well everything has sunk in.