C# 如何使用moq模拟ControllerContext？模拟ControllerContext时出错

我使用的是MOQ框架，我进行了以下单元测试，它失败了，代码下面一行出现了错误消息“Object reference not set to a instance of a Object”

viewCxt.View.Render(viewCxt, writer);  

有谁能告诉我为什么这个考试不及格吗

[Test]
public void can_call_PopulateBankTransactionWorkQueueViewInTransactionMetaDataAjaxResponseObject()
{

    var transactionMetaData = new TransactionMetaDataDTO() { TransactionId = "1", FileId = "1", LockboxNumber = "0402020", DepositDate = "04.26.2011", BatchId = "1" };


    var request = new Mock<HttpRequestBase>();
    request.Setup(r => r.HttpMethod).Returns("GET");
    var mockHttpContext = new Mock<HttpContextBase>();
    mockHttpContext.Setup(c => c.Request).Returns(request.Object);

    var controllerContext = new ControllerContext(mockHttpContext.Object, new Mock<RouteData>().Object, new Mock<ControllerBase>().Object); 

    var checkWorkQueueController = new CheckWorkQueueController(
          activeDirectorySecurityManager.Object,  businessObjectAdapter, httpRequestObjectHelper.Object, invoiceRepos.Object,  new HtmlHelpers());

    checkWorkQueueController.ControllerContext = controllerContext;
    Assert.DoesNotThrow(() => checkWorkQueueController.PopulateBatchTreeSelectorViewInTransactionMetaDataAjaxResponseObject(transactionMetaData));
}

internal void PopulateBatchTreeSelectorViewInTransactionMetaDataAjaxResponseObject(TransactionMetaDataDTO transactionMetaDataDTO)
{

    var checkWorkQueueViewModel = new CheckWorkQueueViewModel(securityManager, businessObjectAdapter);
    SetActiveFileAndLockbox(transactionMetaDataDTO, checkWorkQueueViewModel, transactionMetaDataDTO.FileId, transactionMetaDataDTO.LockboxNumber);
    transactionMetaDataDTO.BatchTreeSelectorView = htmlHelpers.RenderViewToString(ApplicationConstants.CheckWorkQueueViewPath + ApplicationConstants.BatchTreeSelectorViewFileName, this, checkWorkQueueViewModel);
}

public string RenderViewToString<T>(string viewPath, ControllerBase controller, T model)
{
        controller.ViewData.Model = model;
        using (var writer = new StringWriter())
        {
            var view = new WebFormView(viewPath);
            var vdd = new ViewDataDictionary<T>(model);
            var viewCxt = new ViewContext(controller.ControllerContext, view, vdd, new TempDataDictionary(), writer);
            viewCxt.View.Render(viewCxt, writer);  //ERROR throwing here
            return writer.ToString();
        }
}

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调试实际需要在Mock上设置的内容的一个好方法是使用MockBehavior.Strict选项创建它。所以

var mockHttpContext = new Mock<HttpContextBase>();

var mockHttpContext=new Mock（）；

变成

var mockHttpContext = new Mock<HttpContextBase>(MockBehavior.Strict);

var mockHttpContext=newmock（MockBehavior.Strict）；

---

然后，当测试需要来自您尚未设置的上下文的内容时，您的测试将失败并出现MockException。您可以稍后恢复到松散选项。

不幸的是，任何标准模拟对象都不会产生此错误。

var mockHttpContext = new Mock<HttpContextBase>(MockBehavior.Strict);