c# - QueryString 真的不区分大小写吗？

Question

我在一个支付平台上工作，为了响应支付，一个简单的 GET 调用，在查询字符串中有一些参数，是对我的听众的:

http://localhost/mytest/listener?TIMECREATED=04.08.2015+12%3A22%3A27&statoattuale=OK&PREVIOUSSTATE=IN&CURRENTSTATE=payment_approved&tipomessaggio=PAYMENT_STATE&DESCRIZIONE=CAMBIO+DI+STATO&datacreazione=04.08.2015+12%3A22%3A27&stabilimento=xxxxxx&MerchantNumber=xxxxxx&descrizione=CAMBIO+DI+STATO&OBJECT=PAYMENT&TIMEGENERATED=04.08.2015+12%3A23%3A17&MERCHANTNUMBER=xxxxxx&statoprecedente=IN&MERCHANTACCOUNT=xxxxxx&numeroOrdine=myOrderNo&numeroCommerciante=xxxxxx&datagenerazione=04.08.2015+12%3A23%3A17&ORDERNUMBER=myOrderNo&Stabilimento=xxxxxx&mac=CaWJiRCxbWH%2FsNFMvHUD2A%3D%3D&MAC=AnsEvRHkvMwRL%2FgehVtnhA%3D%3D

当我检查 Request.QueryString 时，我得到的是乱七八糟的参数顺序和大小写。似乎它们是在第一次出现时用调整后的大小写重新排序的。像这样:

TIMECREATED=04.08.2015 12:22:27&statoattuale=OK&PREVIOUSSTATE=IN&CURRENTSTATE=payment_approved&tipomessaggio=PAYMENT_STATE&DESCRIZIONE=CAMBIO DI STATO&DESCRIZIONE=CAMBIO DI STATO&datacreazione=04.08.2015 12:22:27&stabilimento=xxxxxx&stabilimento=xxxxxx&MerchantNumber=xxxxxx&MerchantNumber=xxxxxx&OBJECT=PAYMENT&TIMEGENERATED=04.08.2015 12:23:17&statoprecedente=IN&MERCHANTACCOUNT=999988801&numeroOrdine=myOrderNo&numeroCommerciante=xxxxxx&datagenerazione=04.08.2015 12:23:17&ORDERNUMBER=myOrderNo&mac=CaWJiRCxbWH/sNFMvHUD2A==&mac=AnsEvRHkvMwRL/gehVtnhA==

对我来说这看起来像是一个错误，因为 RFC3986 指出:

When a URI uses components of the generic syntax, the component syntax equivalence rules always apply; namely, that the scheme and host are case-insensitive and therefore should be normalized to lowercase. For example, the URI is equivalent to http://www.example.com/. The other generic syntax components are assumed to be case-sensitive unless specifically defined otherwise by the scheme (see Section 6.2.3).

目前我通过手动解析 Url.Query 解决了我的问题，但我仍然认为 Request.QueryString 的行为方式不正确。

有人可以阐明这件事吗？

Answer 1

不幸的是，API 没有提供使 Request.QueryString 集合区分大小写(或 Request.Headers 或 Request.Form 集合，就此而言)。

然而，通过反射进行一些逆向工程，这并不难。

public class CaseSensitiveQueryStringCollection : System.Collections.Specialized.NameValueCollection
{
    public CaseSensitiveQueryStringCollection(string queryString, bool urlencoded, System.Text.Encoding encoding)
        // This makes it case sensitive, the default is StringComparer.OrdinalIgnoreCase
        : base(StringComparer.Ordinal)
    {
        if (queryString.StartsWith("?"))
        {
            queryString = queryString.Substring(1);
        }

        this.FillFromString(queryString, urlencoded, encoding);
    }

    internal void FillFromString(string s, bool urlencoded, System.Text.Encoding encoding)
    {
        int num = (s != null) ? s.Length : 0;
        for (int i = 0; i < num; i++)
        {
            int startIndex = i;
            int num4 = -1;
            while (i < num)
            {
                char ch = s[i];
                if (ch == '=')
                {
                    if (num4 < 0)
                    {
                        num4 = i;
                    }
                }
                else if (ch == '&')
                {
                    break;
                }
                i++;
            }
            string str = null;
            string str2 = null;
            if (num4 >= 0)
            {
                str = s.Substring(startIndex, num4 - startIndex);
                str2 = s.Substring(num4 + 1, (i - num4) - 1);
            }
            else
            {
                str2 = s.Substring(startIndex, i - startIndex);
            }
            if (urlencoded)
            {
                base.Add(HttpUtility.UrlDecode(str, encoding), HttpUtility.UrlDecode(str2, encoding));
            }
            else
            {
                base.Add(str, str2);
            }
            if ((i == (num - 1)) && (s[i] == '&'))
            {
                base.Add(null, string.Empty);
            }
        }
    }
}

用法

var query = new CaseSensitiveQueryStringCollection(
    HttpContext.Current.Request.Url.Query, 
    true, 
    System.Text.Encoding.UTF8);

当您使用像 ?MAC=123&mac=456 这样的查询字符串时，您可以看到它们是分开的。