DNX Core 5.0中Attribute.IsDefined放在哪里? [英] Where did Attribute.IsDefined go in DNX Core 5.0?

问题描述

我正在尝试检查属性是否具有属性.过去，这是通过以下方式完成的:

I'm trying to check if a property has an attribute. This used to be done with:

Attribute.IsDefined(propertyInfo, typeof(AttributeClass));

但是我收到警告，说它在DNX Core 5.0中不可用(它仍然在DNX 4.5.1中).

However I get a warning that it's not available in DNX Core 5.0 (it still is in DNX 4.5.1).

它是否尚未实现，还是像其他与类型/反射相关的东西一样被迁移了?

Has it not been implemented yet or has it moved like other type/reflection related stuff?

我正在使用beta7.

I'm using beta7.

推荐答案

实际上，在 System.Reflection.Extensions 包中似乎有一个IsDefined扩展方法. .用法:

There actually seems to be an IsDefined extension method in the System.Reflection.Extensions package. Usage:

var defined = propertyInfo.IsDefined(typeof(AttributeClass));

您需要包括System.Reflection命名空间.可以在此处.在MemberInfo旁边，它也可以在Assembly，Module和ParameterInfo上工作.

You need to include the System.Reflection namespace. The reference source code can be found here. Beside MemberInfo, it works on Assembly, Module and ParameterInfo too.

这比使用GetCustomAttribute 可能更快.

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原始帖子:

看起来它尚未移植到.NET Core.同时，您可以使用GetCustomAttribute来确定是否在属性上设置了属性:

Looks like it's not ported to .NET Core yet. In the mean while you can use GetCustomAttribute to determine whether an attribute is set on a property:

bool defined = propertyInfo.GetCustomAttribute(typeof(AttributeClass)) != null;

您可以将其烘焙为扩展方法:

You could bake this into an extension method:

public static class MemberInfoExtensions
{
    public static bool IsAttributeDefined<TAttribute>(this MemberInfo memberInfo)
    {
        return memberInfo.IsAttributeDefined(typeof(TAttribute));
    }

    public static bool IsAttributeDefined(this MemberInfo memberInfo, Type attributeType)
    {
        return memberInfo.GetCustomAttribute(attributeType) != null;
    }
}

并像这样使用它:

bool defined = propertyInfo.IsAttributeDefined<AttributeClass>();

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