c# - 为什么在 Equals 方法中忽略了 Uri 的片段？

Question

我正在尝试根据对象的 URI 维护对象集合:

public class ConceptCollection : KeyedCollection<Uri, Concept> {
    protected override Uri GetKeyForItem(Concept item) {
        return item.Uri;
    } 
}

但是，URI 通常仅根据 Uri 的片段而有所不同。因此，以下会导致错误:

ConceptCollection wines = new ConceptCollection();
Concept red = new Concept("http://www.w3.org/2002/07/owl#RedWine");
Concept white = new Concept("http://www.w3.org/2002/07/owl#WhiteWine");
wines.Add(red);
wines.Add(white); // Error: An item with the same key has already been added.

根据 http://msdn.microsoft.com/en-us/library/f83xtf15.aspx :

The Equals method compares the two instances without regard to user information ( UserInfo) and fragment ( Fragment) parts that they might contain. For example, given the URIs http://www.contoso.com/index.htm#search and http://user:password@www.contoso.com/index.htm, the Equals method would return true.

我已经辞职了，不得不绕过这个。但为什么它会这样呢？我可以看到用户信息的逻辑，但看不到片段的逻辑。

Answer 1

来自 RFC 2396 :

4.1. Fragment Identifier

When a URI reference is used to perform a retrieval action on the identified resource, the optional fragment identifier, separated from the URI by a crosshatch ("#") character, consists of additional reference information to be interpreted by the user agent after the retrieval action has been successfully completed. As such, it is not part of a URI, but is often used in conjunction with a URI.

添加的重点是我的，这也是 Uri.Equals 实现中未考虑该片段的原因。

在您的示例中，您正在检索的资源的 URI 是:http://www.w3.org/2002/07/owl

片段由用户代理处理，对资源的实际检索没有任何意义或影响。