我有一组类似于下面列表中的url

http://somesite.example/backup/lol.php?id=1&server=4&location=us http://somesite.example/news.php?article=1&lang=en

我已经设法获得查询字符串使用以下代码:

myurl = longurl.Split('?');
NameValueCollection qs = HttpUtility.ParseQueryString(myurl [1]);

foreach (string lol in qs)
{
    // results will return
}

但它只返回参数 id、服务器、位置等等,基于所提供的URL。

我需要的是向现有的查询字符串添加/追加值。

例如,使用URL:

http://somesite.example/backup/index.php?action=login&attempts=1

我需要改变查询字符串参数的值:

操作 = 登录 1

尝试= 11

如您所见,我为每个值附加了“1”。我需要从一个字符串中获得一组url,其中包含不同的查询字符串,并在末尾为每个参数添加一个值&再次将它们添加到列表中。


你可以使用HttpUtility。ParseQueryString方法和一个UriBuilder,它提供了一种很好的方式来处理查询字符串参数,而不用担心解析、URL编码等问题:

string longurl = "http://somesite.example/news.php?article=1&lang=en";
var uriBuilder = new UriBuilder(longurl);
var query = HttpUtility.ParseQueryString(uriBuilder.Query);
query["action"] = "login1";
query["attempts"] = "11";
uriBuilder.Query = query.ToString();
longurl = uriBuilder.ToString();
// "http://somesite.example:80/news.php?article=1&lang=en&action=login1&attempts=11"

我将Darin的答案包装到一个可重用的扩展方法中。

public static class UriExtensions
{
    /// <summary>
    /// Adds the specified parameter to the Query String.
    /// </summary>
    /// <param name="url"></param>
    /// <param name="paramName">Name of the parameter to add.</param>
    /// <param name="paramValue">Value for the parameter to add.</param>
    /// <returns>Url with added parameter.</returns>
    public static Uri AddParameter(this Uri url, string paramName, string paramValue)
    {
        var uriBuilder = new UriBuilder(url);
        var query = HttpUtility.ParseQueryString(uriBuilder.Query);
        query[paramName] = paramValue;
        uriBuilder.Query = query.ToString();

        return uriBuilder.Uri;
    }
}

提供的答案在相对url上有问题,例如“/some/path/” 这是URI和UriBuilder类的一个限制,很难理解,因为我不认为相对url在查询操作时会有任何问题。

下面是一个在。net 4中编写和测试的解决方法,它既适用于绝对路径也适用于相对路径:

(小提示:这应该也适用于。net 4.5,你只需要改变propInfo。到propInfo.GetValue(values)

  public static class UriExtensions{
    /// <summary>
    ///     Adds query string value to an existing url, both absolute and relative URI's are supported.
    /// </summary>
    /// <example>
    /// <code>
    ///     // returns "www.domain.example/test?param1=val1&amp;param2=val2&amp;param3=val3"
    ///     new Uri("www.domain.example/test?param1=val1").ExtendQuery(new Dictionary&lt;string, string&gt; { { "param2", "val2" }, { "param3", "val3" } });
    ///
    ///     // returns "/test?param1=val1&amp;param2=val2&amp;param3=val3"
    ///     new Uri("/test?param1=val1").ExtendQuery(new Dictionary&lt;string, string&gt; { { "param2", "val2" }, { "param3", "val3" } });
    /// </code>
    /// </example>
    /// <param name="uri"></param>
    /// <param name="values"></param>
    /// <returns></returns>
    public static Uri ExtendQuery(this Uri uri, IDictionary<string, string> values) {
      var baseUrl = uri.ToString();
      var queryString = string.Empty;
      if (baseUrl.Contains("?")) {
        var urlSplit = baseUrl.Split('?');
        baseUrl = urlSplit[0];
        queryString = urlSplit.Length > 1 ? urlSplit[1] : string.Empty;
      }

      NameValueCollection queryCollection = HttpUtility.ParseQueryString(queryString);
      foreach (var kvp in values ?? new Dictionary<string, string>()) {
        queryCollection[kvp.Key] = kvp.Value;
      }
      var uriKind = uri.IsAbsoluteUri ? UriKind.Absolute : UriKind.Relative;
      return queryCollection.Count == 0
        ? new Uri(baseUrl, uriKind)
        : new Uri(string.Format("{0}?{1}", baseUrl, queryCollection), uriKind);
    }

    /// <summary>
    ///     Adds query string value to an existing url, both absolute and relative URI's are supported.
    /// </summary>
    /// <example>
    /// <code>
    ///     // returns "www.domain.example/test?param1=val1&amp;param2=val2&amp;param3=val3"
    ///     new Uri("www.domain.example/test?param1=val1").ExtendQuery(new { param2 = "val2", param3 = "val3" });
    ///
    ///     // returns "/test?param1=val1&amp;param2=val2&amp;param3=val3"
    ///     new Uri("/test?param1=val1").ExtendQuery(new { param2 = "val2", param3 = "val3" });
    /// </code>
    /// </example>
    /// <param name="uri"></param>
    /// <param name="values"></param>
    /// <returns></returns>
    public static Uri ExtendQuery(this Uri uri, object values) {
      return ExtendQuery(uri, values.GetType().GetProperties().ToDictionary
      (
          propInfo => propInfo.Name,
          propInfo => { var value = propInfo.GetValue(values, null); return value != null ? value.ToString() : null; }
      ));
    }
  }

下面是一组测试行为的单元测试:

  [TestFixture]
  public class UriExtensionsTests {
    [Test]
    public void Add_to_query_string_dictionary_when_url_contains_no_query_string_and_values_is_empty_should_return_url_without_changing_it() {
      Uri url = new Uri("http://www.domain.example/test");
      var values = new Dictionary<string, string>();
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test")));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_contains_hash_and_query_string_values_are_empty_should_return_url_without_changing_it() {
      Uri url = new Uri("http://www.domain.example/test#div");
      var values = new Dictionary<string, string>();
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test#div")));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_contains_no_query_string_should_add_values() {
      Uri url = new Uri("http://www.domain.example/test");
      var values = new Dictionary<string, string> { { "param1", "val1" }, { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test?param1=val1&param2=val2")));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_contains_hash_and_no_query_string_should_add_values() {
      Uri url = new Uri("http://www.domain.example/test#div");
      var values = new Dictionary<string, string> { { "param1", "val1" }, { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test#div?param1=val1&param2=val2")));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_contains_query_string_should_add_values_and_keep_original_query_string() {
      Uri url = new Uri("http://www.domain.example/test?param1=val1");
      var values = new Dictionary<string, string> { { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test?param1=val1&param2=val2")));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_is_relative_contains_no_query_string_should_add_values() {
      Uri url = new Uri("/test", UriKind.Relative);
      var values = new Dictionary<string, string> { { "param1", "val1" }, { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=val1&param2=val2", UriKind.Relative)));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_is_relative_and_contains_query_string_should_add_values_and_keep_original_query_string() {
      Uri url = new Uri("/test?param1=val1", UriKind.Relative);
      var values = new Dictionary<string, string> { { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=val1&param2=val2", UriKind.Relative)));
    }

    [Test]
    public void Add_to_query_string_dictionary_when_url_is_relative_and_contains_query_string_with_existing_value_should_add_new_values_and_update_existing_ones() {
      Uri url = new Uri("/test?param1=val1", UriKind.Relative);
      var values = new Dictionary<string, string> { { "param1", "new-value" }, { "param2", "val2" } };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=new-value&param2=val2", UriKind.Relative)));
    }

    [Test]
    public void Add_to_query_string_object_when_url_contains_no_query_string_should_add_values() {
      Uri url = new Uri("http://www.domain.example/test");
      var values = new { param1 = "val1", param2 = "val2" };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test?param1=val1&param2=val2")));
    }

    [Test]
    public void Add_to_query_string_object_when_url_contains_query_string_should_add_values_and_keep_original_query_string() {
      Uri url = new Uri("http://www.domain.example/test?param1=val1");
      var values = new { param2 = "val2" };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("http://www.domain.example/test?param1=val1&param2=val2")));
    }

    [Test]
    public void Add_to_query_string_object_when_url_is_relative_contains_no_query_string_should_add_values() {
      Uri url = new Uri("/test", UriKind.Relative);
      var values = new { param1 = "val1", param2 = "val2" };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=val1&param2=val2", UriKind.Relative)));
    }

    [Test]
    public void Add_to_query_string_object_when_url_is_relative_and_contains_query_string_should_add_values_and_keep_original_query_string() {
      Uri url = new Uri("/test?param1=val1", UriKind.Relative);
      var values = new { param2 = "val2" };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=val1&param2=val2", UriKind.Relative)));
    }

    [Test]
    public void Add_to_query_string_object_when_url_is_relative_and_contains_query_string_with_existing_value_should_add_new_values_and_update_existing_ones() {
      Uri url = new Uri("/test?param1=val1", UriKind.Relative);
      var values = new { param1 = "new-value", param2 = "val2" };
      var result = url.ExtendQuery(values);
      Assert.That(result, Is.EqualTo(new Uri("/test?param1=new-value&param2=val2", UriKind.Relative)));
    }
  }

下面的解决方案适用于ASP。NET 5 (vNext),它使用QueryHelpers类来构建带有参数的URI。

    public Uri GetUri()
    {
        var location = _config.Get("http://iberia.com");
        Dictionary<string, string> values = GetDictionaryParameters();

        var uri = Microsoft.AspNetCore.WebUtilities.QueryHelpers.AddQueryString(location, values);
        return new Uri(uri);
    }

    private Dictionary<string,string> GetDictionaryParameters()
    {
        Dictionary<string, string> values = new Dictionary<string, string>
        {
            { "param1", "value1" },
            { "param2", "value2"},
            { "param3", "value3"}
        };
        return values;
    }

结果URI应该是http://iberia.com?param1=value1&param2=value2&param3=value3


我喜欢Bjorn的答案,但他提供的解决方案是误导性的,因为该方法更新一个现有的参数,而不是添加它,如果它不存在。为了更安全一点,我在下面对它进行了修改。

public static class UriExtensions
{
    /// <summary>
    /// Adds or Updates the specified parameter to the Query String.
    /// </summary>
    /// <param name="url"></param>
    /// <param name="paramName">Name of the parameter to add.</param>
    /// <param name="paramValue">Value for the parameter to add.</param>
    /// <returns>Url with added parameter.</returns>
    public static Uri AddOrUpdateParameter(this Uri url, string paramName, string paramValue)
    {
        var uriBuilder = new UriBuilder(url);
        var query = HttpUtility.ParseQueryString(uriBuilder.Query);

        if (query.AllKeys.Contains(paramName))
        {
            query[paramName] = paramValue;
        }
        else
        {
            query.Add(paramName, paramValue);
        }
        uriBuilder.Query = query.ToString();

        return uriBuilder.Uri;
    }
}

结束了所有URL查询字符串编辑的麻烦

在对Uri类和其他解决方案进行了大量的辛劳和摆弄之后,下面是我的字符串扩展方法来解决我的问题。

using System;
using System.Collections.Specialized;
using System.Linq;
using System.Web;

public static class StringExtensions
{
    public static string AddToQueryString(this string url, params object[] keysAndValues)
    {
        return UpdateQueryString(url, q =>
        {
            for (var i = 0; i < keysAndValues.Length; i += 2)
            {
                q.Set(keysAndValues[i].ToString(), keysAndValues[i + 1].ToString());
            }
        });
    }

    public static string RemoveFromQueryString(this string url, params string[] keys)
    {
        return UpdateQueryString(url, q =>
        {
            foreach (var key in keys)
            {
                q.Remove(key);
            }
        });
    }

    public static string UpdateQueryString(string url, Action<NameValueCollection> func)
    {
        var urlWithoutQueryString = url.Contains('?') ? url.Substring(0, url.IndexOf('?')) : url;
        var queryString = url.Contains('?') ? url.Substring(url.IndexOf('?')) : null;
        var query = HttpUtility.ParseQueryString(queryString ?? string.Empty);

        func(query);

        return urlWithoutQueryString + (query.Count > 0 ? "?" : string.Empty) + query;
    }
}

注意,你可以添加微软的Microsoft. aspnetcore . webutilities nuget包,然后用它来附加值到查询字符串:

QueryHelpers.AddQueryString(longurl, "action", "login1")
QueryHelpers.AddQueryString(longurl, new Dictionary<string, string> { { "action", "login1" }, { "attempts", "11" } });

这更令人沮丧,因为现在(.net 5) MS已经标记了许多(所有)他们的方法,接受字符串而不是Uri为过时。

不管怎样,操纵相对uri的更好方法可能是给它它想要的东西:

var requestUri = new Uri("x://x").MakeRelativeUri(
   new UriBuilder("x://x") { Path = path, Query = query }.Uri);

您可以使用其他答案实际构建查询字符串。