在 MVC 中上传大文件遇到错误

我有一个大小高达 2GB 的.txt文件，我想将该文件从客户端上传到服务器中的文件夹，在上传该文件时，出现错误，页面是这样说的：

An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD) 
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
 Exception Details: System.Runtime.InteropServices.COMException: An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD)
Source Error: 

 An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  
Stack Trace: 

[COMException (0x800704cd): An operation was attempted on a nonexistent network connection. (Exception from HRESULT: 0x800704CD)]
[HttpException (0x80004005): An error occurred while communicating with the remote host. The error code is 0x800704CD.]
   System.Web.Hosting.IIS7WorkerRequest.RaiseCommunicationError(Int32 result, Boolean throwOnDisconnect) +3399867
   System.Web.Hosting.IIS7WorkerRequest.ReadEntityCoreSync(Byte[] buffer, Int32 offset, Int32 size) +9621484
   System.Web.Hosting.IIS7WorkerRequest.ReadEntityBody(Byte[] buffer, Int32 size) +24
   System.Web.HttpRequest.GetEntireRawContent() +315
   System.Web.HttpRequest.GetMultipartContent() +63
   System.Web.HttpRequest.FillInFormCollection() +160
   System.Web.HttpRequest.EnsureForm() +69
   System.Web.HttpRequest.get_Form() +13
   System.Web.HttpRequestWrapper.get_Form() +14
   System.Web.Mvc.HttpRequestExtensions.GetHttpMethodOverride(HttpRequestBase request) +121
   System.Web.Mvc.AcceptVerbsAttribute.IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo) +37
   System.Web.Mvc.HttpGetAttribute.IsValidForRequest(ControllerContext controllerContext, MethodInfo methodInfo) +39
   System.Web.Mvc.ActionMethodSelectorBase.IsValidMethodSelector(ReadOnlyCollection`1 attributes, ControllerContext controllerContext, MethodInfo method) +54
   System.Web.Mvc.ActionMethodSelectorBase.RunSelectionFilters(ControllerContext controllerContext, List`1 methodInfos) +132
   System.Web.Mvc.ActionMethodSelectorBase.FindActionMethods(ControllerContext controllerContext, String actionName) +142
   System.Web.Mvc.ActionMethodSelectorBase.FindActionMethod(ControllerContext controllerContext, String actionName) +104
   System.Web.Mvc.Async.ReflectedAsyncControllerDescriptor.FindAction(ControllerContext controllerContext, String actionName) +54
   System.Web.Mvc.ControllerActionInvoker.FindAction(ControllerContext controllerContext, ControllerDescriptor controllerDescriptor, String actionName) +16
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +114
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1c(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +25
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +468
   System.Web.Mvc.Controller.<BeginExecute>b__14(AsyncCallback asyncCallback, Object callbackState, Controller controller) +18
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +374
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +16
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__3(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +384
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

这是一些代码：

    public ActionResult UploadFile_Post(FormCollection dt, string btn, HttpPostedFileBase uploadFile, FileUpload dataFile)
    {
      string nameFile, getExtension = "";
      nameFile = System.IO.Path.GetFileNameWithoutExtension(uploadFile.FileName.ToString().Trim()) + "_" + usernm.Trim() + "_" + DateTime.Now.ToString("yyyyMMdd_HHmmss").Trim();
      getExtension = System.IO.Path.GetExtension(uploadFile.FileName.ToString().Trim());
      string FilePath = Server.MapPath("~''Upload''" + nameFile + ".txt");
      string pathFile = Server.MapPath("~''Upload''");
      if (System.IO.File.Exists(FilePath))
      {
           System.IO.File.Delete(FilePath);                            
      }
      uploadFile.SaveAs(FilePath);//i think failed at this process
   }

在 Web.config 文件中，我已经为 maxRequestLength 、 executionTimeout 和 maxAllowedContentLength 设置了配置。也许我的代码是错误的，你们能给我更好的上传此类文件的方法吗？谢谢对不起，我的英语不好。

<system.web>
    <httpRuntime executionTimeout="3600" maxRequestLength="102400" 
     appRequestQueueLimit="100" requestLengthDiskThreshold="10024000"/>
</system.web>