由于我必须重用这几次，所以我提出了这个类，它只是帮助抽象查询字符串是如何组成的。

public class UriBuilderExt
{
    private NameValueCollection collection;
    private UriBuilder builder;

    public UriBuilderExt(string uri)
    {
        builder = new UriBuilder(uri);
        collection = System.Web.HttpUtility.ParseQueryString(string.Empty);
    }

    public void AddParameter(string key, string value) {
        collection.Add(key, value);
    }

    public Uri Uri{
        get
        {
            builder.Query = collection.ToString();
            return builder.Uri;
        }
    }

}

使用将被简化成这样:

var builder = new UriBuilderExt("http://example.com/");
builder.AddParameter("foo", "bar<>&-baz");
builder.AddParameter("bar", "second");
var uri = builder.Uri;

将返回uri: http://example.com/?foo=bar%3c%3e%26-baz&bar=second

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));

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"

您可能想看看Flurl[披露:我是作者]，这是一个流畅的URL构建器，带有可选的配套库，可以将其扩展为一个成熟的REST客户机。

var result = await "https://api.com"
    // basic URL building:
    .AppendPathSegment("endpoint")
    .SetQueryParams(new {
        api_key = ConfigurationManager.AppSettings["SomeApiKey"],
        max_results = 20,
        q = "Don't worry, I'll get encoded!"
    })
    .SetQueryParams(myDictionary)
    .SetQueryParam("q", "overwrite q!")

    // extensions provided by Flurl.Http:
    .WithOAuthBearerToken("token")
    .GetJsonAsync<TResult>();

查看文档了解更多细节。完整的软件包在NuGet上可用:

PM>安装包Flurl。Http

或者只是独立的URL构建器:

PM>安装包Flurl

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"));

与罗斯托夫的帖子一样，如果你不想包含对系统的引用。在你的项目中，你可以使用System.Net.Http.Formatting中的FormDataCollection，然后做如下的事情:

使用System.Net.Http.Formatting.FormDataCollection

var parameters = new Dictionary<string, string>()
{
    { "ham", "Glaced?" },
    { "x-men", "Wolverine + Logan" },
    { "Time", DateTime.UtcNow.ToString() },
}; 
var query = new FormDataCollection(parameters).ReadAsNameValueCollection().ToString();