如何将值传递给MVC3母版页(_layout)？

Question

我有一个自定义模型绑定器,它检查身份验证cookie并返回值.

public class UserDataModelBinder<T> : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {

        if (controllerContext.RequestContext.HttpContext.Request.IsAuthenticated)
        {
            var cookie =
                controllerContext.RequestContext.HttpContext.Request.Cookies[FormsAuthentication.FormsCookieName];

            if (cookie == null)
                return null;

            var decrypted = FormsAuthentication.Decrypt(cookie.Value);

            if (!string.IsNullOrWhiteSpace(decrypted.UserData))
                return JsonSerializer.DeserializeFromString<T>(decrypted.UserData);
        }

        return null;
    }
}

如果我需要使用它,我只需要将它传递给动作.一切正常.

public ActionResult Index(UserData userData)
{
    AccountLoginWidgetVM model = new AccountLoginWidgetVM();
    if (null != userData)
        model.UserData = userData;

    return View(userData);
}

但是,我想在我的母版页中使用它,因为一旦用户登录,我想在每个页面的顶部显示他们的信息.我尝试了一些东西,但是不能让它发挥作用

 @Html.RenderPartial("LoginPartial", ???model here??)  

Answer 1

我们这样做了:

1. 为masterpages定义了单独的viewmodel.

   public class MasterPageViewModel
   {
       public Guid CurrentUserId { get; set; }
       public string CurrentUserFullName { get; set; }
   }
   

2. 添加了注入过滤器和过滤器

   public class MasterPageViewModelInjectorFilterProvider: IFilterProvider
   {
       public IEnumerable<Filter> GetFilters(ControllerContext controllerContext, ActionDescriptor actionDescriptor)
       {
           return new [] {new Filter(new MasterPageViewModelInjectorFilter(), FilterScope.Action, null), };
       }
   
       private class MasterPageViewModelInjectorFilter: IResultFilter
       {
           public void OnResultExecuting(ResultExecutingContext filterContext)
           {
               var viewResult = filterContext.Result as ViewResult;
               if (viewResult == null)
                   return;
   
               if (viewResult.ViewBag.MasterPageViewModel != null)
                   return;
   
               //setup model whichever way you want
               var viewModel = new MasterPageViewModel();
               //inject model into ViewBag
               viewResult.ViewBag.MasterPageViewModel = viewModel;
           }
   
           public void OnResultExecuted(ResultExecutedContext filterContext)
           {
           }
       }
   }
   

3. 配置筛选提供程序

   //in Application_Start
   FilterProviders.Providers.Add(new MasterPageViewModelInjectorFilterProvider());
   

4. 在master中使用:

   ViewBag.MasterPageViewModel
   

这样你就可以得到很好的解耦结构.当然你可以将它与依赖注入结合起来(我们这样做,但为了清楚起见,我把它留了出来)并根据你想要的方式为每个动作配置你的动作过滤器.