Upraviť

Zdieľať cez

Use 'System.HashCode.Combine' (IDE0070)

Property Value
Rule ID IDE0070
Title Use System.HashCode.Combine
Category Style
Subcategory Language rules (expression-level preferences)
Applicable languages C# and Visual Basic
Options dotnet_prefer_system_hash_code

Overview

This rule recommends the use of the System.HashCode.Combine method to compute a hash code instead of using custom hash code computation logic.

Options

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

dotnet_prefer_system_hash_code

Property Value Description
Option name dotnet_prefer_system_hash_code
Option values true Prefer to use System.HashCode.Combine for hash code computation.
false Don't prefer to use System.HashCode.Combine for hash code computation.
Default option value true

Example

class B
{
    public override int GetHashCode() => 0;
}

class C : B
{
    int j;

    // Code with violations
    public override int GetHashCode()
    {
        // IDE0070: GetHashCode can be simplified.
        var hashCode = 339610899;
        hashCode = hashCode * -1521134295 + base.GetHashCode();
        hashCode = hashCode * -1521134295 + j.GetHashCode();
        return hashCode;
    }

    // Fixed code
    public override int GetHashCode()
    {
        return System.HashCode.Combine(base.GetHashCode(), j);
    }
}

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 IDE0070
// The code that's violating the rule is on this line.
#pragma warning restore IDE0070

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

[*.{cs,vb}]
dotnet_diagnostic.IDE0070.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

  • Last updated on