ReSharper 2018.1 Help

Code Inspection: Type or member is never used (non-private accessibility)

Unused types or members might indicate dead code, which can occur, for example, after changing your codebase. ReSharper detects methods that are not called and types that are not used.

To reduce code size and simplify its maintenance, ReSharper suggests you to either remove or comment out the unused type or member.

For this inspection to work, you need either or both of the following:

  • The simplified global usage checking is enabled — Show unused non-private type members when solution-wide analysis is off on the Code Inspection | Settings page of ReSharper options.
  • The solution-wide analysis is enabled — Enable solution-wide analysis on the Code Inspection | Settings page of ReSharper options.

Of course, there are a lot of cases where symbols can be used in less traditional ways — via reflection, different frameworks — or they just could be designed as a public API. In all those cases you would want to suppress this inspection.
You can always suppress usage-checking inspections locally with a comment or an attribute, but the recommended way is to decorate unused symbols with code annotation attributes. There are two attributes for this purpose: [UsedImplicitly] and [PublicAPI], which are functionally similar, but let you and your teammates understand how the symbol is actually used.

You can also suppress these inspections with any custom attribute. To do so, mark the definition of that attribute with the [MeansImplicitUse] attribute.

Last modified: 24 April 2018

See Also