异常将部分视图呈现为包含另一个部分视图的字符串

Question

我正在尝试将部分视图呈现为字符串以在 JSON 对象内返回。我有这个代码来做到这一点：

/// <summary>

/// Render razor view to a string.

/// </summary>

/// <param name="model">Model sent to view.</param>

/// <param name="filePath">Path to the view location in project hierarchy.</param>

/// <returns>String with the html code of returned view.</returns>

public static string Func_GetRazorViewAsString(object model, string filePath)

{

    var st = new StringWriter();

    var context = new HttpContextWrapper(HttpContext.Current);

    var routeData = new RouteData();

    var controllerContext = new ControllerContext(new RequestContext(context, routeData), new FakeController());

    var razor = new RazorView(controllerContext, filePath, null, false, null);

    razor.Render(new ViewContext(controllerContext, razor, new ViewDataDictionary(model), new TempDataDictionary(), st), st);

    return st.ToString();

}

当 View 不包含 PartialView 时它工作得很好，但是当要呈现的视图调用另一个 Partial View 时它会抛出异常。例如：

@using Anpr_Web_Manager.App_GlobalResources

@model IEnumerable<Anpr_Web_Manager.Models.DetectionCardViewModel>

@{

    int iCountElementsRow = 0;

    int iNumberElements = Model.Count();

    int iNumNavigationPages = (int)Math.Ceiling(iNumberElements / (double)3);

}

    <div class="col-12 bootstrap-carousel">

        <div id="carouselDetections" class="carousel slide" data-ride="carousel" data-interval="false">

            @if (iNumberElements != 0)

            {

                @:<ol class="carousel-indicators">

                    <li data-target="#carouselDetections" data-slide-to="0" class="active"></li>

                    for (int i = 1; i < iNumNavigationPages; i++)

                {

                    <li data-target="#carouselDetections" data-slide-to="@i"></li>

                    }

                @:</ol>

            }

异常消息是：

“RouteData 必须包含一个名为 'controller' 且具有非空字符串值的项目。”

请问，我该如何解决？我知道我可以复制和粘贴第二个 Partial View 的代码，但这不是我最好的解决方案，因为我在其他地方使用了这个 Partial View，我不想重复相同的代码。

Answer 1

使用此方法将视图呈现为字符串：public static string RenderViewToString(ControllerContext context, string viewPath, object viewModel = null, bool partial = false){&nbsp; &nbsp; // get the ViewEngine for this view&nbsp; &nbsp; ViewEngineResult viewEngineResult = null;&nbsp; &nbsp; if (partial)&nbsp; &nbsp; &nbsp; &nbsp; viewEngineResult = ViewEngines.Engines.FindPartialView(context, viewPath);&nbsp; &nbsp; else&nbsp; &nbsp; &nbsp; &nbsp; viewEngineResult = ViewEngines.Engines.FindView(context, viewPath, null);&nbsp; &nbsp; if (viewEngineResult == null)&nbsp; &nbsp; &nbsp; &nbsp; throw new FileNotFoundException("View cannot be found.");&nbsp; &nbsp; // get the view and attach the model to view data&nbsp; &nbsp; var view = viewEngineResult.View;&nbsp; &nbsp; context.Controller.ViewData.Model = viewModel;&nbsp; &nbsp; string result = null;&nbsp; &nbsp; using (var sw = new StringWriter())&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; var ctx = new ViewContext(context, view, context.Controller.ViewData, context.Controller.TempData, sw);&nbsp; &nbsp; &nbsp; &nbsp; view.Render(ctx, sw);&nbsp; &nbsp; &nbsp; &nbsp; result = sw.ToString();&nbsp; &nbsp; }&nbsp; &nbsp; return result;}如果您致电：@foreach (var item in Model.SomeIEnumerableModel){&nbsp; &nbsp; @Html.Partial("~/Views/SomePath/SomeViewTwo.cshtml", item);}在“父局部视图”中。可以使用这个在控制器中调用它（假设您从 ajax 请求返回 json，并且该RenderViewToString方法位于调用控制器中）：public ActionResult TestViewToString(){&nbsp; &nbsp; var viewModel = new TestViewModel();&nbsp; &nbsp; // Populate ViewModel here ...&nbsp; &nbsp; string data = RenderViewToString(ControllerContext, "~/Views/SomePath/SomeViewOne.cshtml", viewModel, true);&nbsp; &nbsp; return Json(data, JsonRequestBehavior.AllowGet);}