Overview of code analysis for .NET in Visual Studio
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
Visual Studio can perform code analysis of managed code in two ways: with legacy analysis, also known as FxCop static analysis of managed assemblies, and with the more modern .NET Compiler Platform-based code analyzers. .NET Compiler Platform-based code analyzers, which analyze your code live as you type, replace legacy FxCop static code analysis, which only analyzes compiled code.