csvhelper引发了错误“无法访问处置对象”。从FTP解析CSV文件时

Question

我正在尝试使用csvhelper解析.csv文件。如果我尝试将数据解析为FTP路径中的动态对象，我会发现一个错误

无法访问处置对象。对象名称：'System.net.sockets.networkStream'。

这是我的代码

private WebRequest CreateRequest(string method)
{
    WebRequest req = null;

    try
    {
        req = WebRequest.Create(_host + folderpath);
        req.Method = method;
        req.Credentials = _credentials;
    }
    catch(Exception ex)
    {
    }

    return req;     
}

public void ReadCSVData(string filename)
{
    List<string> myList = new List<string>();
    folderpath = folderpath + "/" + filename;

    var request = CreateRequest(WebRequestMethods.Ftp.DownloadFile);

    FtpWebResponse response = (FtpWebResponse)request.GetResponse();
    Stream responseStream = response.GetResponseStream();

    using (StreamReader reader = new StreamReader(responseStream, System.Text.Encoding.UTF8))
    {
        using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))
        {
            var records = csvReader.GetRecords<dynamic>().ToList();
        }
    }
}

为错误的stackTrace：

   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.FtpDataStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   at System.IO.StreamReader.ReadBuffer(Char[] userBuffer, Int32 userOffset, Int32 desiredChars, Boolean& readToUserBuffer)
   at System.IO.StreamReader.Read(Char[] buffer, Int32 index, Int32 count)
   at CsvHelper.CsvParser.Read()
   at CsvHelper.CsvReader.Read()
   at CsvHelper.CsvReader.<GetRecords>d__87`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at FleetcheckDownLoad.FTP.ReadCSVData(String filename) in C:\FleetcheckDownLoad\FleetcheckDownLoad\FTP.cs:line 188
   at FleetcheckDownLoad.DownLoad.dataGridView1_CellDoubleClick(Object sender, DataGridViewCellEventArgs e) in C:\FleetcheckDownLoad\FleetcheckDownLoad\DownLoad.cs:line 58
   at System.Windows.Forms.DataGridView.OnCellDoubleClick(DataGridViewCellEventArgs e)
   at System.Windows.Forms.DataGridView.OnDoubleClick(EventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.DataGridView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)