c# - 需要一个关于如何从 Accept-Language 请求 header 中获取首选语言的示例

Question

我需要一个代码示例或库来解析 Accept-Language header 并返回我首选的语言。 RFC2616指出:

The Accept-Language request-header field is similar to Accept, but restricts the set of natural languages that are preferred as a response to the request. Language tags are defined in section 3.10.

   Accept-Language = "Accept-Language" ":"
                     1#( language-range [ ";" "q" "=" qvalue ] )
   language-range  = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" ) 

Each language-range MAY be given an associated quality value which represents an estimate of the user's preference for the languages specified by that range. The quality value defaults to "q=1".

进一步阅读表明有太多的“可选”、“应该”、“可能”和其他轮词阻止我重新发明轮子——我只想知道用户喜欢什么语言，任何浏览器都会回答这个问题每天提问十亿次。

任何语言的任何代码片段(Lisp 和汇编程序除外)都会有所帮助。

非常感谢!

Answer 1

解决方案:

namespace ConsoleApplication
{
    using System;
    using System.Linq;
    using System.Net.Http.Headers;

    class Program
    {
        static void Main(string[] args)
        {
            string header = "en-ca,en;q=0.8,en-us;q=0.6,de-de;q=0.4,de;q=0.2";
            var languages = header.Split(',')
                .Select(StringWithQualityHeaderValue.Parse)
                .OrderByDescending(s => s.Quality.GetValueOrDefault(1));
        }
    }
}

结果: