Impossible d'accéder à un fichier fermé lors de l'utilisation de FileStream.CopyToAsync?

J'ai la méthode suivante,

    public Task SaveFileContentsAsync(string filePath, Stream stream)
    {
        using (var fileStream = new FileStream(filePath, FileMode.Create))
        {
            return stream.CopyToAsync(fileStream);
        }
    }

Cette méthode simple enregistrement des flux sur le disque. Lorsque j'appelle cette méthode avec HttpPostedFileBase.InputStream je suis arriver,

Exception Details: System.ObjectDisposedException: Cannot access a closed file.
[ObjectDisposedException: Cannot access a closed file.]
System.IO.__Error.FileNotOpen() +57
System.IO.FileStream.Write(Byte[] array, Int32 offset, Int32 count) +10549618
System.IO.Stream.<BeginWriteInternal>b__11(Object param0) +59
System.Threading.Tasks.Task`1.InnerInvoke() +3132781
System.Threading.Tasks.Task.Execute() +45
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +93
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
System.IO.Stream.EndWrite(IAsyncResult asyncResult) +85
System.IO.FileStream.EndWrite(IAsyncResult asyncResult) +24
System.IO.Stream.<BeginEndWriteAsync>b__17(Stream stream, IAsyncResult asyncResult) +24
System.Threading.Tasks.FromAsyncTrimPromise`1.Complete(TInstance thisRef, Func`3 endMethod, IAsyncResult asyncResult, Boolean requiresSynchronization) +44
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +93
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
System.IO.<CopyToAsyncInternal>d__2.MoveNext() +253
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +93
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
System.Runtime.CompilerServices.TaskAwaiter.GetResult() +21
S.Web.Controllers.<Add>d__15.MoveNext() in c:\Users\A\Source\Test\STest\S.Web\Controllers\ProductController.cs:66
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +93
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +52
System.Web.Mvc.Async.TaskAsyncActionDescriptor.EndExecute(IAsyncResult asyncResult) +84
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeAsynchronousActionMethod>b__36(IAsyncResult asyncResult) +17
System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +32
System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +50
System.Web.Mvc.Async.<>c__DisplayClass48.<InvokeActionMethodFilterAsynchronouslyRecursive>b__41() +225
System.Web.Mvc.Async.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +34
System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +26
System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +10
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +48
System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +13
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +53
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +39
System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +12
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +28
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +53
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +29
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36
System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +53
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +31
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9514812
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

OriginalL'auteur user960567 | 2014-05-06

async-await c#c#-5.0

12

C'est parce que le flux est disposé sur la ligne suivante. L'appel est asynchrone.. et, par conséquent, tombe à la Dispose appel à la fin de la using bloc.

await la Task retourné à partir de CopyToAsync de sorte que le fileStream instance est toujours disponible pour elle que de faire ce qu'il doit faire:
```
public async Task SaveFileContentsAsync(string filePath, Stream stream)
{
using (var fileStream = new FileStream(filePath, FileMode.Create))
{
await stream.CopyToAsync(fileStream);
}
}
```
Merci beaucoup

OriginalL'auteur Simon Whitehead

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