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CA1000: Do not declare static members on generic types

  • Article
Property Value
Rule ID CA1000
Title Do not declare static members on generic types
Category Design
Fix is breaking or non-breaking Breaking
Enabled by default in .NET 9 No

Cause

A generic type contains a static (Shared in Visual Basic) member.

By default, this rule only looks at externally visible types, but this is configurable.

Rule description

When a static member of a generic type is called, the type argument must be specified for the type. When a generic instance member that does not support inference is called, the type argument must be specified for the member. The syntax for specifying the type argument in these two cases is different and easily confused, as the following calls demonstrate:

' Shared method in a generic type.
GenericType(Of Integer).SharedMethod()

' Generic instance method that does not support inference.
someObject.GenericMethod(Of Integer)()

// Static method in a generic type.
GenericType<int>.StaticMethod();

// Generic instance method that does not support inference.
someObject.GenericMethod<int>();

Generally, both of the prior declarations should be avoided so that the type argument does not have to be specified when the member is called. This results in a syntax for calling members in generics that is no different from the syntax for non-generics.

How to fix violations

To fix a violation of this rule, remove the static member or change it to an instance member.

When to suppress warnings

Do not suppress a warning from this rule. Providing generics in a syntax that is easy to understand and use reduces the time that is required to learn and increases the adoption rate of new libraries.

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable CA1000
// The code that's violating the rule is on this line.
#pragma warning restore CA1000

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.CA1000.severity = none

For more information, see How to suppress code analysis warnings.

Configure code to analyze

Use the following option to configure which parts of your codebase to run this rule on.

You can configure this option for just this rule, for all rules that it applies to, or for all rules in this category (Design) that it applies to. For more information, see Code quality rule configuration options.

Include specific API surfaces

You can configure which parts of your codebase to run this rule on, based on their accessibility. For example, to specify that the rule should run only against the non-public API surface, add the following key-value pair to an .editorconfig file in your project:

dotnet_code_quality.CAXXXX.api_surface = private, internal

See also