在 MVC 4 中使用路由更改 URL 参数

Question

我的几个 API 函数允许名为“attribute”和“attributeDelimiter”（单数）的参数，这意味着预期 URL 的格式为

SomeController/SomeAction?aaa=bbb&attribute=ccc&attributeDelimiter=ddd.

我希望在这些参数名称中也支持复数 - 'attributes' 和 'attributesDelimiter'。

1. 有没有办法在 RouteConfig 中重写 url？ （将复数名称变为单数）
2. 如果这不可能或不是最佳做法，那么进行这种重写的最佳方法是什么？

Answer 1

MVC 不对查询字符串值使用路由。查询字符串值由value providers 提供给操作方法。因此，要解决这个问题，您只需要一个自定义值提供程序来处理单数或复数的情况。

示例

using System;
using System.Collections.Specialized;
using System.Globalization;
using System.Web.Mvc;

public class SingularOrPluralQueryStringValueProviderFactory : ValueProviderFactory
{
    private readonly string singularKey;
    private readonly string pluralKey;

    public SingularOrPluralQueryStringValueProviderFactory(string singularKey, string pluralKey)
    {
        if (string.IsNullOrEmpty(singularKey))
            throw new ArgumentNullException("singularKey");
        if (string.IsNullOrEmpty(pluralKey))
            throw new ArgumentNullException("pluralKey");

        this.singularKey = singularKey;
        this.pluralKey = pluralKey;
    }

    public override IValueProvider GetValueProvider(ControllerContext controllerContext)
    {
        return new SingularOrPluralQueryStringValueProvider(this.singularKey, this.pluralKey, controllerContext.HttpContext.Request.QueryString);
    }
}

public class SingularOrPluralQueryStringValueProvider : IValueProvider
{
    private readonly string singularKey;
    private readonly string pluralKey;
    private readonly NameValueCollection queryString;


    public SingularOrPluralQueryStringValueProvider(string singularKey, string pluralKey, NameValueCollection queryString)
    {
        if (string.IsNullOrEmpty(singularKey))
            throw new ArgumentNullException("singularKey");
        if (string.IsNullOrEmpty(pluralKey))
            throw new ArgumentNullException("pluralKey");

        this.singularKey = singularKey;
        this.pluralKey = pluralKey;
        this.queryString = queryString;
    }

    public bool ContainsPrefix(string prefix)
    {
        return this.GetSingularOrPluralValue(prefix) != null;
    }

    public ValueProviderResult GetValue(string key)
    {
        var value = this.GetSingularOrPluralValue(key);
        return (value != null) ? 
            new ValueProviderResult(value, value.ToString(), CultureInfo.InvariantCulture) : 
            null;
    }

    private bool IsKeyMatch(string key)
    {
        return (this.singularKey.Equals(key, StringComparison.OrdinalIgnoreCase) ||
            this.pluralKey.Equals(key, StringComparison.OrdinalIgnoreCase));
    }

    private string GetSingularOrPluralValue(string key)
    {
        if (this.IsKeyMatch(key))
        {
            return this.queryString[this.singularKey] ?? this.queryString[this.pluralKey];
        }
        return null;
    }
}

用法

public class MvcApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();

        WebApiConfig.Register(GlobalConfiguration.Configuration);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
        AuthConfig.RegisterAuth();

        // Insert our value provider factories at the beginning of the list 
        // so they override the default QueryStringValueProviderFactory
        ValueProviderFactories.Factories.Insert(
            0, new SingularOrPluralQueryStringValueProviderFactory("attribute", "attributes"));
        ValueProviderFactories.Factories.Insert(
            1, new SingularOrPluralQueryStringValueProviderFactory("attributeDelimiter", "attributesDelimiter"));
    }
}

现在，在您的操作方法甚至模型的属性中，无论值是在查询字符串中指定为单数还是复数，这些值都将被填充。如果查询字符串中同时包含单数和复数，则单数优先。

public ActionResult Index(string attribute, string attributeDelimiter)
{
    return View();
}