如何在 .NET 中将查询字符串解析为 NameValueCollection

How to parse a query string into a NameValueCollection in .NET

提问by Nathan Smith

I would like to parse a string such as p1=6&p2=7&p3=8into a NameValueCollection.

我想解析字符串，如p1=6&p2=7&p3=8成NameValueCollection。

What is the most elegant way of doing this when you don't have access to the Page.Requestobject?

当您无法访问Page.Request对象时，最优雅的方法是什么？

回答by Guy Starbuck

There's a built-in .NET utility for this: HttpUtility.ParseQueryString

有一个内置的 .NET 实用程序： HttpUtility.ParseQueryString

// C#
NameValueCollection qscoll = HttpUtility.ParseQueryString(querystring);

' VB.NET
Dim qscoll As NameValueCollection = HttpUtility.ParseQueryString(querystring)

You may need to replace querystringwith new Uri(fullUrl).Query.

您可能需要替换querystring为new Uri(fullUrl).Query.

回答by Scott Dorman

HttpUtility.ParseQueryString will work as long as you are in a web app or don't mind including a dependency on System.Web. Another way to do this is:

只要您在 Web 应用程序中或不介意包含对 System.Web 的依赖项，HttpUtility.ParseQueryString 就可以使用。另一种方法是：

NameValueCollection queryParameters = new NameValueCollection();
string[] querySegments = queryString.Split('&');
foreach(string segment in querySegments)
{
   string[] parts = segment.Split('=');
   if (parts.Length > 0)
   {
      string key = parts[0].Trim(new char[] { '?', ' ' });
      string val = parts[1].Trim();

      queryParameters.Add(key, val);
   }
}

回答by James Skimming

A lot of the answers are providing custom examples because of the accepted answer's dependency on System.Web. From the Microsoft.AspNet.WebApi.ClientNuGet package there is a UriExtensions.ParseQueryString, method that can also be used:

由于接受的答案依赖于System.Web ，许多答案都提供了自定义示例。从Microsoft.AspNet.WebApi.ClientNuGet包有一个UriExtensions.ParseQueryString，方法还可以用于：

var uri = new Uri("https://stackoverflow.com/a/22167748?p1=6&p2=7&p3=8");
NameValueCollection query = uri.ParseQueryString();

So if you want to avoid the System.Webdependency and don't want to roll your own, this is a good option.

因此，如果您想避免System.Web依赖项并且不想自己滚动，这是一个不错的选择。

回答by densom

I wanted to remove the dependency on System.Web so that I could parse the query string of a ClickOnce deployment, while having the prerequisites limited to the "Client-only Framework Subset".

我想删除对 System.Web 的依赖，以便我可以解析 ClickOnce 部署的查询字符串，同时将先决条件限制为“仅客户端框架子集”。

I liked rp's answer. I added some additional logic.

我喜欢 rp 的回答。我添加了一些额外的逻辑。

public static NameValueCollection ParseQueryString(string s)
    {
        NameValueCollection nvc = new NameValueCollection();

        // remove anything other than query string from url
        if(s.Contains("?"))
        {
            s = s.Substring(s.IndexOf('?') + 1);
        }

        foreach (string vp in Regex.Split(s, "&"))
        {
            string[] singlePair = Regex.Split(vp, "=");
            if (singlePair.Length == 2)
            {
                nvc.Add(singlePair[0], singlePair[1]);
            }
            else
            {
                // only one key with no value specified in query string
                nvc.Add(singlePair[0], string.Empty);
            }
        }

        return nvc;
    }

回答by Josh Brown

I needed a function that is a little more versatile than what was provided already when working with OLSC queries.

在处理 OLSC 查询时，我需要一个比已经提供的功能更通用的函数。

• Values may contain multiple equal signs
• Decode encoded characters in both name and value
• Capable of running on Client Framework
• Capable of running on Mobile Framework.

• 值可能包含多个等号
• 解码名称和值中的编码字符
• 能够在客户端框架上运行
• 能够在移动框架上运行。

Here is my solution:

这是我的解决方案：

Public Shared Function ParseQueryString(ByVal uri As Uri) As System.Collections.Specialized.NameValueCollection
    Dim result = New System.Collections.Specialized.NameValueCollection(4)
    Dim query = uri.Query
    If Not String.IsNullOrEmpty(query) Then
        Dim pairs = query.Substring(1).Split("&"c)
        For Each pair In pairs
            Dim parts = pair.Split({"="c}, 2)

            Dim name = System.Uri.UnescapeDataString(parts(0))
            Dim value = If(parts.Length = 1, String.Empty,
                System.Uri.UnescapeDataString(parts(1)))

            result.Add(name, value)
        Next
    End If
    Return result
End Function

It may not be a bad idea to tack <Extension()>on that too to add the capability to Uri itself.

将其<Extension()>添加到 Uri 本身也可能不是一个坏主意。

回答by jvenema

To do this without System.Web, without writing it yourself, and without additional NuGet packages:

要做到这一点System.Web，无需自己编写，无需额外的 NuGet 包：

1. Add a reference to System.Net.Http.Formatting
2. Add using System.Net.Http;

3. Use this code:

   new Uri(uri).ParseQueryString()
   

1. 添加引用 System.Net.Http.Formatting
2. 添加 using System.Net.Http;

3. 使用此代码：

   new Uri(uri).ParseQueryString()
   

https://msdn.microsoft.com/en-us/library/system.net.http.uriextensions(v=vs.118).aspx

https://msdn.microsoft.com/en-us/library/system.net.http.uriextensions(v=vs.118).aspx

回答by Amadeus Sánchez

If you want to avoid the dependency on System.Web that is required to use HttpUtility.ParseQueryString, you could use the Uriextension method ParseQueryStringfound in System.Net.Http.

如果你想避免需要使用上的System.Web依赖HttpUtility.ParseQueryString，您可以使用Uri扩展方法ParseQueryString中发现的System.Net.Http。

Make sure to add a reference (if you haven't already) to System.Net.Httpin your project.

确保System.Net.Http在您的项目中添加一个引用（如果您还没有）。

Note that you have to convert the response body to a valid Uriso that ParseQueryString(in System.Net.Http)works.

请注意，您必须将响应正文转换为有效的，Uri以便ParseQueryString(in System.Net.Http) 工作。

string body = "value1=randomvalue1&value2=randomValue2";

// "http://localhost/query?" is added to the string "body" in order to create a valid Uri.
string urlBody = "http://localhost/query?" + body;
NameValueCollection coll = new Uri(urlBody).ParseQueryString();

回答by Thomas Levesque

I just realized that Web API Clienthas a ParseQueryStringextension method that works on a Uriand returns a HttpValueCollection:

我刚刚意识到Web API 客户端有一个ParseQueryString扩展方法，它适用于 aUri并返回 a HttpValueCollection：

var parameters = uri.ParseQueryString();
string foo = parameters["foo"];

回答by rp.

    private void button1_Click( object sender, EventArgs e )
    {
        string s = @"p1=6&p2=7&p3=8";
        NameValueCollection nvc = new NameValueCollection();

        foreach ( string vp in Regex.Split( s, "&" ) )
        {
            string[] singlePair = Regex.Split( vp, "=" );
            if ( singlePair.Length == 2 )
            {
                nvc.Add( singlePair[ 0 ], singlePair[ 1 ] );    
            }    
        }
    }

回答by alex1kirch

HttpUtility.ParseQueryString(Request.Url.Query)return is HttpValueCollection(internal class). It inherits from NameValueCollection.

HttpUtility.ParseQueryString(Request.Url.Query)返回是HttpValueCollection（内部类）。它继承自NameValueCollection.

    var qs = HttpUtility.ParseQueryString(Request.Url.Query);
    qs.Remove("foo"); 

    string url = "~/Default.aspx"; 
    if (qs.Count > 0)
       url = url + "?" + qs.ToString();

    Response.Redirect(url);