WebException
   在 System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult, TransportContext& context)
   在 System.Net.HttpWebRequest.EndGetRequestStream(IAsyncResult asyncResult)
   在 DynamicClass.WebDAVClient.ReadCallback(IAsyncResult result)
   在 System.Net.LazyAsyncResult.Complete(IntPtr userToken)
   在 System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   在 System.Net.ContextAwareResult.Complete(IntPtr userToken)
   在 System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
   在 System.Net.HttpWebRequest.SetResponse(Exception E)
   在 System.Net.ConnectStream.ProcessWriteCallDone(ConnectionReturnResult returnResult)
   在 System.Net.ConnectStream.CallDone(ConnectionReturnResult returnResult)
   在 System.Net.ConnectStream.IOError(Exception exception, Boolean willThrow)
   在 System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)
   在 System.Net.LazyAsyncResult.Complete(IntPtr userToken)
   在 System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
   在 System.Net.TlsStream.ResumeIOWorker(Object result)
   在 System.Net.TlsStream.WakeupPendingIO(IAsyncResult ar)
   在 System.Net.LazyAsyncResult.Complete(IntPtr userToken)
   在 System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
   在 System.Net.Security.SslState.FinishHandshake(Exception e, AsyncProtocolRequest asyncRequest)
   在 System.Net.Security.SslState.PartialFrameCallback(AsyncProtocolRequest asyncRequest)
   在 System.Net.AsyncProtocolRequest.CompleteRequest(Int32 result)
   在 System.Net.FixedSizeReader.CheckCompletionBeforeNextRead(Int32 bytes)
   在 System.Net.FixedSizeReader.ReadCallback(IAsyncResult transportResult)
   在 System.Net.LazyAsyncResult.Complete(IntPtr userToken)
   在 System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   在 System.Net.ContextAwareResult.Complete(IntPtr userToken)
   在 System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
   在 System.Net.Sockets.BaseOverlappedAsyncResult.CompletionPortCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* nativeOverlapped)
   在 System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)

IOException
由于远程方已关闭传输流，身份验证失败。
   在 System.Net.TlsStream.EndWrite(IAsyncResult asyncResult)
   在 System.Net.ConnectStream.WriteHeadersCallback(IAsyncResult ar)