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Remove unnecessary using directives (IDE0005)

  • Article
Property Value
Rule ID IDE0005
Title Remove unnecessary import
Category Style
Subcategory Unnecessary code rules (using directive preferences)
Applicable languages C# and Visual Basic

Overview

This rule flags the following unnecessary constructs. If unnecessary, these constructs can be removed without changing the semantics of the code:

Note

To enable this rule on build, you need to enable XML documentation comments for the project. For more information, see dotnet/roslyn issue 41640.

Options

This rule has no associated code-style options.

Example

// Code with violations
using System;
using System.IO;    // IDE0005: Using directive is unnecessary
class C
{
    public static void M()
    {
        Console.WriteLine("Hello");
    }
}

// Fixed code
using System;
class C
{
    public static void M()
    {
        Console.WriteLine("Hello");
    }
}

' Code with violations
Imports System.IO   ' IDE0005: Imports statement is unnecessary
Class C
    Public Shared Sub M()
        Console.WriteLine("Hello")
    End Sub
End Class

' Fixed code
Class C
    Public Shared Sub M()
        Console.WriteLine("Hello")
    End Sub
End Class

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 IDE0005
// The code that's violating the rule is on this line.
#pragma warning restore IDE0005

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0005.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.

Property Value
Rule ID IDE0005
Title Open declaration can be removed
Category Style
Applicable languages F#
Options None

Overview

This rule flags unnecessary open declarations. For example, open System.Collections is unnecessary in the following snippet:

open System.Collections

printfn "Hello from F#"

See also