对于那些不想包括系统。Web在项目中还没有使用它，你可以使用System.Net.Http的FormUrlEncodedContent，并做如下的事情:

keyvaluepair版本

string query;
using(var content = new FormUrlEncodedContent(new KeyValuePair<string, string>[]{
    new KeyValuePair<string, string>("ham", "Glazed?"),
    new KeyValuePair<string, string>("x-men", "Wolverine + Logan"),
    new KeyValuePair<string, string>("Time", DateTime.UtcNow.ToString()),
})) {
    query = content.ReadAsStringAsync().Result;
}

字典的版本

string query;
using(var content = new FormUrlEncodedContent(new Dictionary<string, string>()
{
    { "ham", "Glaced?"},
    { "x-men", "Wolverine + Logan"},
    { "Time", DateTime.UtcNow.ToString() },
})) {
    query = content.ReadAsStringAsync().Result;
}

我找不到比创建一个扩展方法来将Dictionary转换为QueryStringFormat更好的解决方案。Waleed A.K.提出的解决方案也不错。

遵循我的解决方案:

创建扩展方法:

public static class DictionaryExt
{
    public static string ToQueryString<TKey, TValue>(this Dictionary<TKey, TValue> dictionary)
    {
        return ToQueryString<TKey, TValue>(dictionary, "?");
    }

    public static string ToQueryString<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, string startupDelimiter)
    {
        string result = string.Empty;
        foreach (var item in dictionary)
        {
            if (string.IsNullOrEmpty(result))
                result += startupDelimiter; // "?";
            else
                result += "&";

            result += string.Format("{0}={1}", item.Key, item.Value);
        }
        return result;
    }
}

和他们:

var param = new Dictionary<string, string>
          {
            { "param1", "value1" },
            { "param2", "value2" },
          };
param.ToQueryString(); //By default will add (?) question mark at begining
//"?param1=value1&param2=value2"
param.ToQueryString("&"); //Will add (&)
//"&param1=value1&param2=value2"
param.ToQueryString(""); //Won't add anything
//"param1=value1&param2=value2"

我的答案与公认的答案/其他答案在全球范围内并无不同。我只是尝试为Uri类型创建一个扩展方法，它接受可变数量的参数。

public static class UriExtensions
{
    public static Uri AddParameter(this Uri url, params (string Name, string Value)[] @params)
    {
        if (!@params.Any())
        {
            return url;
        }

        UriBuilder uriBuilder = new(url);

        NameValueCollection query = HttpUtility.ParseQueryString(uriBuilder.Query);

        foreach (var param in @params)
        {
            query[param.Name] = param.Value.Trim();
        }

        uriBuilder.Query = query.ToString();

        return uriBuilder.Uri;
    }
}

使用的例子:

var uri = new Uri("http://someuri.com")
    .AddParameter(
       ("p1.name", "p1.value"),
       ("p2.name", "p2.value"),
       ("p3.name", "p3.value"));

或者简单地使用我的Uri扩展

Code

public static Uri AttachParameters(this Uri uri, NameValueCollection parameters)
{
    var stringBuilder = new StringBuilder();
    string str = "?";
    for (int index = 0; index < parameters.Count; ++index)
    {
        stringBuilder.Append(str + parameters.AllKeys[index] + "=" + parameters[index]);
        str = "&";
    }
    return new Uri(uri + stringBuilder.ToString());
}

使用

Uri uri = new Uri("http://www.example.com/index.php").AttachParameters(new NameValueCollection
                                                                           {
                                                                               {"Bill", "Gates"},
                                                                               {"Steve", "Jobs"}
                                                                           });

结果

http://www.example.com/index.php?Bill=Gates&Steve=Jobs

在一个ASP。在asp.net Core项目中，你可以使用QueryHelpers类，在Microsoft.AspNetCore.WebUtilities命名空间中。NET Core，或。NET标准2.0 NuGet包给其他消费者:

// using Microsoft.AspNetCore.WebUtilities;
var query = new Dictionary<string, string>
{
    ["foo"] = "bar",
    ["foo2"] = "bar2",
    // ...
};

var response = await client.GetAsync(QueryHelpers.AddQueryString("/api/", query));

避免taras中描述的双重编码问题。roshko的答案，并保持容易使用查询参数的可能性，你可以使用uriBuilder.Uri.ParseQueryString()而不是HttpUtility.ParseQueryString()。