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Remove unused private member (IDE0051)

  • Article
Property Value
Rule ID IDE0051
Title Remove unused private member
Category CodeQuality
Subcategory Unnecessary code rules (expression-level preferences)
Applicable languages C# and Visual Basic

Overview

This rule flags unused private methods, fields, properties, and events that have no read or write references.

Options

This rule has no associated code-style options.

Example

// Code with violations
class C
{
    // IDE0051: Remove unused private members
    private readonly int _fieldPrivate;
    private int PropertyPrivate => 1;
    private int GetNumPrivate() => 1;

    // No IDE0051
    internal readonly int FieldInternal;
    private readonly int _fieldPrivateUsed;
    public int PropertyPublic => _fieldPrivateUsed;
    private int GetNumPrivateUsed() => 1;
    internal int GetNumInternal() => GetNumPrivateUsed();
    public int GetNumPublic() => GetNumPrivateUsed();
}

// Fixed code
class C
{
    // No IDE0051
    internal readonly int FieldInternal;
    private readonly int _fieldPrivateUsed;
    public int PropertyPublic => _fieldPrivateUsed;
    private int GetNumPrivateUsed() => 1;
    internal int GetNumInternal() => GetNumPrivateUsed();
    public int GetNumPublic() => GetNumPrivateUsed();
}

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 IDE0051
// The code that's violating the rule is on this line.
#pragma warning restore IDE0051

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0051.severity = none

To disable this entire category of rules, set the severity for the category to none in the configuration file.

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

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

See also