C# 9.0 in a Nutshell

Chapter 13. Diagnostics

When things go wrong, it’s important that information is available to aid in diagnosing the problem. An Integrated Development Environment (IDE) or debugger can assist greatly to this effect—but it is usually available only during development. After an application ships, the application itself must gather and record diagnostic information. To meet this requirement, .NET provides a set of facilities to log diagnostic information, monitor application behavior, detect runtime errors, and integrate with debugging tools if available.

Some diagnostic tools and APIs are Windows specific because they rely on features of the Windows operating system. In an effort to prevent platform-specific APIs from cluttering the .NET BCL, Microsoft has shipped them in separate NuGet packages that you can optionally reference. There are more than a dozen Windows-specific packages, which you can reference all at once with the Microsoft.Windows.Compatibility “master” package.

The types in this chapter are defined primarily in the System.Diagnostics namespace.

Conditional Compilation

You can conditionally compile any section of code in C# with preprocessor directives. Preprocessor directives are special instructions to the compiler that begin with the # symbol (and, unlike other C# constructs, must appear on a line of their own). Logically, they execute before the main compilation takes place (although in practice, the compiler processes them during the lexical parsing phase). ...