WebException: 基础连接已经关闭: 服务器关闭了本应保持活动状态的连接。
--Status: KeepAliveFailure
StackTrace:
   在 System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   在 DynamicClass.WebDAVClient.FinishUpload(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.ResubmitWrite(ConnectStream oldStream, Boolean suppressWrite)
   在 System.Net.HttpWebRequest.EndWriteHeaders_Part2()
   在 System.Net.HttpWebRequest.EndWriteHeaders(Boolean async)
   在 System.Net.HttpWebRequest.WriteHeadersCallback(WebExceptionStatus errorStatus, ConnectStream stream, Boolean async)
   在 System.Net.LazyAsyncResult.Complete(IntPtr userToken)
   在 System.Net.LazyAsyncResult.ProtectedInvokeCallback(Object result, IntPtr userToken)
   在 System.Net.Security._SslStream.StartWriting(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   在 System.Net.Security._SslStream.WriteCallback(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: 无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接。。
StackTrace:
   在 System.Net.Security._SslStream.EndRead(IAsyncResult asyncResult)
   在 System.Net.TlsStream.EndRead(IAsyncResult asyncResult)
   在 System.Net.Connection.ReadCallback(IAsyncResult asyncResult)

SocketException: 远程主机强迫关闭了一个现有的连接。
--ErrorCode: 10054
--Message: 远程主机强迫关闭了一个现有的连接。
--SocketErrorCode: ConnectionReset
StackTrace:
   在 System.Net.Sockets.Socket.EndReceive(IAsyncResult asyncResult)
   在 System.Net.Sockets.NetworkStream.EndRead(IAsyncResult asyncResult)