ASP.NET MVC不明确的操作方法

MVC不支持仅基于签名的方法重载,因此这将失败:

public ActionResult MyMethod(int someInt) { /* ... */ }
public ActionResult MyMethod(string someString) { /* ... */ }

然而,它 做 基于属性的支持方法重载:

[RequireRequestValue("someInt")]
public ActionResult MyMethod(int someInt) { /* ... */ }

[RequireRequestValue("someString")]
public ActionResult MyMethod(string someString) { /* ... */ }

public class RequireRequestValueAttribute : ActionMethodSelectorAttribute {
    public RequireRequestValueAttribute(string valueName) {
        ValueName = valueName;
    }
    public override bool IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo) {
        return (controllerContext.HttpContext.Request[ValueName] != null);
    }
    public string ValueName { get; private set; }
}

在上面的示例中,属性简单地说“如果键 XXX 请求中存在。“如果路由(controllerContext.requestContext)中包含的信息更适合您的目的,您还可以按该信息进行筛选。

路线中的参数 {roleId} , {applicationName} 和 {roleName} 不匹配操作方法中的参数名称。我不知道这是否重要,但这使得弄清楚你的意图变得更加困难。

您的itemID是否符合可以通过regex匹配的模式?如果是这样,那么您可以在路由中添加一个约束,这样只有与模式匹配的URL才会被标识为包含一个itemID。

如果您的itemID只包含数字,那么这将起作用:

routes.MapRoute("AssignRemove",
                "Items/{action}/{itemId}",
                new { controller = "Items" },
                new { itemId = "\d+" }
                );

编辑:还可以向 AssignRemovePretty 走这两条路线 {parentName} 和 {itemName} 是必需的。

编辑2:另外,由于您的第一个操作只是重定向到您的第二个操作,您可以通过重命名第一个操作来消除一些歧义。

// Method #1
public ActionResult AssignRemovePretty(string parentName, string itemName) { 
    // Logic to retrieve item's ID here...
    string itemId = ...;
    return RedirectToAction("Assign", itemId);
}

// Method #2
public ActionResult Assign(string itemId, string searchTerm, int? page) { ... }

然后在路由中指定操作名称以强制调用正确的方法:

routes.MapRoute("AssignRemove",
                "Items/Assign/{itemId}",
                new { controller = "Items", action = "Assign" },
                new { itemId = "\d+" }
                );

routes.MapRoute("AssignRemovePretty",
                "Items/Assign/{parentName}/{itemName}",
                new { controller = "Items", action = "AssignRemovePretty" },
                new { parentName = "\w+", itemName = "\w+" }
                );

另一种方法是重命名其中一个方法,这样就不会发生冲突。例如

// GET: /Movies/Delete/5
public ActionResult Delete(int id = 0)

// POST: /Movies/Delete/5
[HttpPost, ActionName("Delete")]
public ActionResult DeleteConfirmed(int id = 0)

见 http://www.asp.net/mvc/tutorials/getting-started-with-mvc3-part9-cs

最近我利用这个机会改进了@levi的答案,以支持我必须处理的更广泛的场景,例如:多参数支持,匹配其中任何一个(而不是全部),甚至不匹配其中任何一个。

下面是我现在使用的属性:

/// <summary>
/// Flags an Action Method valid for any incoming request only if all, any or none of the given HTTP parameter(s) are set,
/// enabling the use of multiple Action Methods with the same name (and different signatures) within the same MVC Controller.
/// </summary>
public class RequireParameterAttribute : ActionMethodSelectorAttribute
{
    public RequireParameterAttribute(string parameterName) : this(new[] { parameterName })
    {
    }

    public RequireParameterAttribute(params string[] parameterNames)
    {
        IncludeGET = true;
        IncludePOST = true;
        IncludeCookies = false;
        Mode = MatchMode.All;
    }

    public override bool IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo)
    {
        switch (Mode)
        {
            case MatchMode.All:
            default:
                return (
                    (IncludeGET && ParameterNames.All(p => controllerContext.HttpContext.Request.QueryString.AllKeys.Contains(p)))
                    || (IncludePOST && ParameterNames.All(p => controllerContext.HttpContext.Request.Form.AllKeys.Contains(p)))
                    || (IncludeCookies && ParameterNames.All(p => controllerContext.HttpContext.Request.Cookies.AllKeys.Contains(p)))
                    );
            case MatchMode.Any:
                return (
                    (IncludeGET && ParameterNames.Any(p => controllerContext.HttpContext.Request.QueryString.AllKeys.Contains(p)))
                    || (IncludePOST && ParameterNames.Any(p => controllerContext.HttpContext.Request.Form.AllKeys.Contains(p)))
                    || (IncludeCookies && ParameterNames.Any(p => controllerContext.HttpContext.Request.Cookies.AllKeys.Contains(p)))
                    );
            case MatchMode.None:
                return (
                    (!IncludeGET || !ParameterNames.Any(p => controllerContext.HttpContext.Request.QueryString.AllKeys.Contains(p)))
                    && (!IncludePOST || !ParameterNames.Any(p => controllerContext.HttpContext.Request.Form.AllKeys.Contains(p)))
                    && (!IncludeCookies || !ParameterNames.Any(p => controllerContext.HttpContext.Request.Cookies.AllKeys.Contains(p)))
                    );
        }
    }

    public string[] ParameterNames { get; private set; }

    /// <summary>
    /// Set it to TRUE to include GET (QueryStirng) parameters, FALSE to exclude them:
    /// default is TRUE.
    /// </summary>
    public bool IncludeGET { get; set; }

    /// <summary>
    /// Set it to TRUE to include POST (Form) parameters, FALSE to exclude them:
    /// default is TRUE.
    /// </summary>
    public bool IncludePOST { get; set; }

    /// <summary>
    /// Set it to TRUE to include parameters from Cookies, FALSE to exclude them:
    /// default is FALSE.
    /// </summary>
    public bool IncludeCookies { get; set; }

    /// <summary>
    /// Use MatchMode.All to invalidate the method unless all the given parameters are set (default).
    /// Use MatchMode.Any to invalidate the method unless any of the given parameters is set.
    /// Use MatchMode.None to invalidate the method unless none of the given parameters is set.
    /// </summary>
    public MatchMode Mode { get; set; }

    public enum MatchMode : int
    {
        All,
        Any,
        None
    }
}

有关进一步的信息和如何实现示例,请查看 this blog post 我就这个话题写的。

routes.MapRoute("AssignRemove",
                "Items/{parentName}/{itemName}",
                new { controller = "Items", action = "Assign" }
                );

考虑使用MVC控件测试路由库来测试路由

"Items/parentName/itemName".Route().ShouldMapTo<Items>(x => x.Assign("parentName", itemName));