Make anonymous function static (IDE0320)

Property	Value
Rule ID	IDE0320
Title	Make anonymous function static
Category	Style
Subcategory	Language rules (modifier preferences)
Applicable languages	C#
Options	csharp_prefer_static_anonymous_function

Overview

This style rule flags anonymous functions that can be marked static. Marking them as static prevents local variables from being captured, which would result in a memory allocation.

Options

Options specify the behavior that you want the rule to enforce. For information about configuring options, see Option format.

csharp_prefer_static_anonymous_function

Property	Value	Description
Option name	csharp_prefer_static_anonymous_function
Option values	true	Prefer anonymous functions to be marked static
	false	Disables the rule
Default option value	true

Example

// Code with violations.
M(x => x + 1);
M(delegate (int x) { return x + 1; });

void M(Func<int, int> f) { }

// Fixed code.
M(static x => x + 1);
M(static delegate (int x) { return x + 1; });

void M(Func<int, int> f) { }

Suppress a warning

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

#pragma warning disable IDE0320
// The code that's violating the rule is on this line.
#pragma warning restore IDE0320

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0320.severity = none

To disable all of the code-style rules, set the severity for the category Style to none in the configuration file.

[*.{cs,vb}]
dotnet_analyzer_diagnostic.category-Style.severity = none

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

See also

• Static anonymous functions