Question

我正在尝试从派生自List的MVC Controller返回一个csv文件。我想出了以下控制器代码，它基于我从docs和SO问题中读取的内容。我一定是错过了一些东西，因为我正在通过“无法访问封闭的溪流”获得黄色死亡屏幕...

[ObjectDisposedException: Cannot access a closed Stream.]
   System.IO.__Error.StreamIsClosed() +59
   System.IO.MemoryStream.Read(Byte[] buffer, Int32 offset, Int32 count) +14731549
   System.Web.Mvc.FileStreamResult.WriteFile(HttpResponseBase response) +93
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +88
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +831
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +81
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +185
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +38
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +29
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +38
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +43
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +38
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +607
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +134

这是堆栈跟踪：

using

如果我在流的parse_url()块内返回结果，流怎么关闭？

Answer 1

你应该删除：

using (memoryStream)

FileStreamResult将dispose memoryStream for you。

您的代码不起作用的原因是从memoryStream读取的实际工作不在您的代码中 - 它位于调用fileStream.WriteFile的MVC代码中。但是该代码在调用堆栈的更高处执行。当WriteFile被调用（需要memoryStream）时，您已经处理了它。

为什么封闭流上的ASP.NET MVC控制器FileStreamResult错误？

1 个答案: