CA1002: Do not expose generic lists
Note
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| Item | Value |
|---|---|
| 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 that is designed for performance and not inheritance. System.Collections.Generic.List<T> does not contain virtual members that make it easier to change the behavior of an inherited class. 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 that is 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
CA1005: Avoid excessive parameters on generic types
CA1010: Collections should implement generic interface
CA1000: Do not declare static members on generic types
CA1006: Do not nest generic types in member signatures
CA1004: Generic methods should provide type parameter
CA1003: Use generic event handler instances
CA1007: Use generics where appropriate