Do not expose generic lists
TypeName |
DoNotExposeGenericLists |
CheckId |
CA1002 |
Category |
Microsoft.Design |
Breaking Change |
Breaking |
Cause
A type contains an externally visible member that is a System.Collections.Generic.List<T> type, returns a System.Collections.Generic.List<T> type, or whose signature includes a System.Collections.Generic.List<T> parameter.
Rule Description
System.Collections.Generic.List<T> is a generic collection designed for performance not inheritance. System.Collections.Generic.List<T> does not contain virtual members that make it easier to implement new behaviors. The following generic collections are designed for inheritance and should be exposed instead of System.Collections.Generic.List<T>.
How to Fix Violations
To fix a violation of this rule, change the System.Collections.Generic.List<T> type to one of the generic collections designed for inheritance.
When to Suppress Warnings
Do not suppress a warning from this rule unless the assembly that raises this warning is not meant to be a reusable library. For example, it would be safe to suppress this warning in a performance tuned application where a performance benefit was gained from the use of generic lists.
Related Rules
Avoid excessive parameters on generic types
Collections should implement generic interface
Do not declare static members on generic types
Do not nest generic types in member signatures
Generic methods should provide type parameter
Use generic event handler instances
Use generics where appropriate