如何检查返回视图是PartialViewResult类型还是ViewUserControl类型

Question

在方法CreateView()中(在下面检查我的视图引擎)或在我的自定义操作过滤器中(也在下面)，我必须以某种方式检查我们请求的视图是否是ViewUserControl。因为否则我会说错话

“当视图是ViewUserControl时不能指定主名称”。

当我在modal=true中有“QueryString”时，视图请求是ViewUsercontrol，因为您不能在ViewUserControls上设置母版页(很明显)。

这是我现在的自定义视图引擎代码：

    public class PendingViewEngine : VirtualPathProviderViewEngine
    {
        public PendingViewEngine()
        {
            // This is where we tell MVC where to look for our files. 
            /* {0} = view name or master page name       
             * {1} = controller name      */
            MasterLocationFormats = new[] {"~/Views/Shared/{0}.master", "~/Views/{0}.master"};
            ViewLocationFormats = new[]
                                    {
                                        "~/Views/{1}/{0}.aspx", "~/Views/Shared/{0}.aspx", "~/Views/Shared/{0}.ascx",
                                        "~/Views/{1}/{0}.ascx"
                                    };
            PartialViewLocationFormats = new[] {"~/Views/{1}/{0}.ascx", "~/Views/Shared/{0}.ascx"};
        }

        protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)
        {
            return new WebFormView(partialPath, "");
        }

        protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
        {
            return new WebFormView(viewPath, masterPath);
        }
}

我的行动过滤器：

public class CanReturnModalView : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        // setup the request, view and data
        HttpRequestBase request = filterContext.RequestContext.HttpContext.Request;

        bool modal = false;

        if (request.QueryString["modal"] != null)
            modal = bool.Parse(request.QueryString["modal"]);

        if (filterContext.Result is ViewResult)
        {
            ViewResult view = (ViewResult) (filterContext.Result);

            // replace the view Master page file with Modal Masterpage
            if (modal)
                view.MasterName = "AdministrationModal";

            filterContext.Result = view;
        }
        else if (filterContext.Result is RedirectToRouteResult)
        {
            RedirectToRouteResult redirect = (RedirectToRouteResult) filterContext.Result;
            // append modal route value to the redirect result if modal was requested
            if (modal)
                redirect.RouteValues.Add("modal", true);

            filterContext.Result = redirect;
        }
    }
}

上面的ViewEngine在这样的调用中失败：

<% Html.RenderAction("Display", "MyController", new { zoneslug = "some-zone-slug" });%>

我在这里所做的动作是：

        public ActionResult Display(string zoneslug)
        {
            WidgetZone zone;

            if (!_repository.IsUniqueSlug(zoneslug))
                zone = (WidgetZone) _repository.GetInstance(zoneslug);
            else
            {
// do something here
            }

// WidgetZone used here is WidgetZone.ascx, so a partial
            return View("WidgetZone", zone);
        }

我不能使用RenderPartial，因为您不能以向RenderPartial发送路由值的方式将路由值发送到RenderAction。据我所知，没有办法像RouteValueDictionary ()那样向RenderPartial()提供RenderAction()。

Answer 1

您可以通过调用PartialView而不是视图来实现所描述的行为：

像现在一样创建视图：

  <% Html.RenderAction("PartialIndex", new { test = "input" }); %>

如你所见，它没有什么特别之处。

然后，在控制器操作中，只需调用PartialView而不是View：

public ActionResult PartialIndex(string test)
{
    var viewResult = PartialView("PartialIndex", (object)test);
    return viewResult;
}

并重写视图方法，以便在将模态参数传递到查询字符串时重写主名称。

public bool IsModal
{
    get
    {
        var modalParameter = Request.QueryString["modal"];

        if (string.IsNullOrEmpty(modalParameter))
            return false;

        bool modalValue;
        var success = bool.TryParse(modalParameter, out modalValue);

        return success && modalValue;
    }
}

protected override ViewResult View(string viewName, string masterName, object model)
{
    if (IsModal)
        masterName = "Alternate";
    return base.View(viewName, masterName, model);
}

只有在呈现实际视图(而不是部分视图)时，视图方法才会被覆盖，因此可以安全地假定可以设置masterName。

Answer 2

试试这个(未经测试)。FindView返回一个ViewEngineResults，该ViewEngineResults具有一个名为IView View的属性，该属性可以是PartialViewResult。如果不存在，只需检查并返回并使用空主。

public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
{
    if( base.FindView(controllerContext, viewName, "", useCache).View is PartialViewResult )
        return base.FindView(controllerContext, viewName, "", useCache);

    if (controllerContext.HttpContext.Request.IsAjaxRequest())
        return base.FindView(controllerContext, viewName, "Modal", useCache);

    return base.FindView(controllerContext, viewName, "Site", useCache);
} 

}