Ninject绑定属性与构造函数参数筛选 [英] Ninject Binding Attribute to Filter with Constructor Arguments

问题描述

我看了尽可能多的答案，因为我能为这一点，但他们似乎功亏一篑一个细节的。

I read as many answers as I could for this, but they seem to fall short of one detail.

麻烦的是绑定的动作过滤器（由控制器注入了服务）到相应的属性，我一直无法弄清楚如何从属性到绑定的过滤器通过参数/属性值时。下面是code和低于预期的我fake- code：

The trouble is when binding an action filter (with a service injected by controller) to a corresponding attribute, I've been unable to figure out how to pass parameter/property values from the attribute to its bound filter. Below is the code, and below that my intended fake-code:

过滤器和放大器;属性

public class AuthorizationFilter : IAuthorizationFilter
{
    private readonly IAuthorizationService _authorizationService;
    private readonly UserRoles _requiredRoles;   // Enum

    public AuthorizationFilter(IAuthorizationService authorizationService, UserRoles requiredRoles)
    {
        _authorizationService = authorizationService;
        _requiredRoles = requiredRoles;
    }

    public void OnAuthorization(AuthorizationContext filterContext)
    {
        if (filterContext.HttpContext.Session == null)
            HandleUnauthorizedRequest(filterContext);
        else {
            var authorized = _authorizationService.IsUserInRole((UserSessionInfoViewModel) filterContext.HttpContext.Session["user"], _requiredRoles);
            if (!authorized)
                HandleUnauthorizedRequest(filterContext);
            // else TODO: deal with cache... 
        }
    }
}

public class RequireRolesAttribute : FilterAttribute
{
    public readonly UserRoles RequiredRoles;

    public RequireRolesAttribute(UserRoles requiredRoles)
    {
        RequiredRoles = requiredRoles;
    }        
}

过滤器/属性绑定

kernel.BindFilter<AuthorizationFilter>(FilterScope.Controller, 0)
      .WhenControllerHas<RequireRolesAttribute>();
kernel.BindFilter<AuthorizationFilter>(FilterScope.Action, 0)
      .WhenActionMethodHas<RequireRolesAttribute>();

这应该确保任何控制器/动作饰[RolesRequired]绑定到过滤器。到现在为止还挺好。现在我想通过属性来声明的角色（很像股票AuthorizeAttribute），并通过这些值到实际执行授权的过滤器。

This should make sure any controller/action decorated with [RolesRequired] is bound to the filter. So far so good. Now I want to declare via the attribute the roles (much like the stock AuthorizeAttribute) and pass those values onto the filter that actually does the authorization.

拟/假code：

[RequireRoles(UserRoles.Author)]
public ActionResult Index()
{
    // blah
}

具体来说，

怎样才能告知角色的AuthorizationFilter？可以过滤/ ninject访问传递给属性的构造函数的参数？可以过滤/ ninject从属性的公共财产拉他们？

What does it take to inform the AuthorizationFilter of the roles? Can the filter/ninject access the arguments passed to the attribute's constructor? Can the filter/ninject pull them from the attributes public property?

有关参考，这些文章是一个巨大的帮助，但不回答这样一件事：

For reference, these articles were a huge help, but don't answer this one thing:

<一个href=\"http://stackoverflow.com/questions/6193414/dependency-injection-with-ninject-and-filter-attribute-for-asp-net-mvc\">Dependency对于asp.net注射Ninject和Filter属性MVC

<一个href=\"http://stackoverflow.com/questions/5572257/custom-authorization-mvc-3-and-ninject-ioc/5572752#5572752\">Custom授权MVC 3和Ninject的IoC

乙Z，雷莫Gloor，别人...我怎样才能做到这一点？

B Z, Remo Gloor, others... how can I accomplish this?

推荐答案

我已经想通了（感谢圣雷莫的指示和文档）。

I have figured it out (thanks to Remo's directions and documentation).

使用适当的 .WithConstructorArgument 扩展是否要绑定到一个控制器或者动作过滤器。例如结合我的动作过滤器是这样的：

Use the appropriate .WithConstructorArgument extension whether you are binding to a Controller or Action filter. For example binding my action filter looks like this:

kernel.BindFilter<AuthorizationFilter>(FilterScope.Action, 0)
      .WhenActionMethodHas<RequireRolesAttribute>()
      .WithConstructorArgumentFromActionAttribute<RequireRolesAttribute>("requiredRoles", o => o.RequiredRoles);

在我理解的 Func键＆LT;> 签名，这一切都变得清晰。我发现处理这种情况最好的办法就是

Once I understood the Func<> signature, it all became clear. The best way I found to handle this was to

1. 请扩展型特异性为我的属性。

1. make the extension type-specific for my attribute

.WithConstructorArgumentFromActionAttribute<TAttribute>()

从获取通过拉姆达回调对象（您的属性）值：

fetch the value from the callback object (your attribute) via lambda:

("argumentName", o => o.PropertyName)

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