{"id":415,"date":"2010-04-02T01:26:07","date_gmt":"2010-04-02T05:26:07","guid":{"rendered":"http:\/\/www.ikriv.com\/blog\/?p=415"},"modified":"2010-04-02T01:26:07","modified_gmt":"2010-04-02T05:26:07","slug":"net-it-is-possible-to-apply-attributes-to-enum-members","status":"publish","type":"post","link":"https:\/\/ikriv.com\/blog\/?p=415","title":{"rendered":".NET: It is possible to apply attributes to enum members"},"content":{"rendered":"

For a long time I was sure it is not supported, because there was no corresponding AttributeTargets<\/a> value.<\/p>\n

It turns out, that you can do it by using AttributeTargets.Field<\/code>. Declaring your attribute class:<\/p>\n

\n

[AttributeUsage<\/span>(AttributeTargets<\/span>.Field)]<\/p>\n

public<\/span> class<\/span> CategoryAttribute<\/span> : Attribute<\/span><\/p>\n<\/div>\n

Declaring your decorated enum:<\/p>\n

\n

enum<\/span> MyEnum<\/span><\/p>\n

{<\/p>\n

    [Category<\/span>("foo"<\/span>)]<\/p>\n

    Foo,<\/p>\n

 <\/p>\n

    [Category<\/span>("This is bar"<\/span>)]<\/p>\n

    Bar,<\/p>\n

 <\/p>\n

    Baz<\/p>\n

}<\/p>\n<\/div>\n

Reading attribute values:<\/p>\n

\n

foreach<\/span> (MyEnum<\/span> x in<\/span> Enum<\/span>.GetValues(typeof<\/span>(MyEnum<\/span>)))<\/p>\n

{<\/p>\n

    MemberInfo<\/span>[] info = typeof<\/span>(MyEnum<\/span>).GetMember(x.ToString());<\/p>\n

    if<\/span> (info.Length != 1)<\/p>\n

    {<\/p>\n

        Console<\/span>.WriteLine("Get {0} members for {1}"<\/span>, info.Length, x);<\/p>\n

        continue<\/span>;<\/p>\n

    }<\/p>\n

 <\/p>\n

    Attribute<\/span>[] categories = Attribute<\/span>.GetCustomAttributes(info[0], typeof<\/span>(CategoryAttribute<\/span>));<\/p>\n

    if<\/span> (categories.Length == 0)<\/p>\n

    {<\/p>\n

        Console<\/span>.WriteLine("{0}: No category"<\/span>, x);<\/p>\n

    }<\/p>\n

    else<\/span><\/p>\n

    {<\/p>\n

        CategoryAttribute<\/span> category = (CategoryAttribute<\/span>)categories[0];<\/p>\n

        Console<\/span>.WriteLine("{0}: {1}"<\/span>, x, category.Category);<\/p>\n

    }<\/p>\n

}<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

For a long time I was sure it is not supported, because there was no corresponding AttributeTargets value. It turns out, that you can do it by using AttributeTargets.Field. Declaring […]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"Layout":"","footnotes":""},"categories":[8],"tags":[],"class_list":["entry","author-ikriv","post-415","post","type-post","status-publish","format-standard","category-cs"],"_links":{"self":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/415","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=415"}],"version-history":[{"count":0,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/415\/revisions"}],"wp:attachment":[{"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=415"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=415"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ikriv.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}