Live Code Analyzers are used to add custom error messages and warnings that appear live as you’re typing, along with automatic code fixes to help you clean them up. They are available as NuGet packages that you add to your projects in Visual Studio 2015.
It is one of the best and helpful key new features of Visual Studio 2015 that lets a NuGet package enable custom warnings and errors in the editor live as you type the code, with automatic code fixes that can clean up those issues for us.
Packages can even be bundled together as a “code-aware library” that pulls in both an API and the domain-specific analyzers to make sure that you stay on course when using it.
We’ll have a targeted guidance from the moment we download the NuGet package. And because these analyzers are part of our project, everyone on your team gets to see the same warnings.
Edit 1 :
Analyzers have rules attached to them like below :
These rules focus on the most critical problems in your code,
including potential security holes, application crashes, and other
important logic and design errors. You should include this rule set in
any custom rule set you create for your projects.