从Web服务调用时，管道已结束

Question

我写了一个.aspx网页来测试我的网络服务。 Web服务将调用外部exe来进行加密。

System.Diagnostics.Process p = new System.Diagnostics.Process();
p.StartInfo.FileName = "pgp.exe";
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.UseShellExecute = false;
p.StartInfo.CreateNoWindow = true;
p.Start();

pgp.exe可以成功启动。但在以下

发生例外

try
{
    BinaryWriter inBinWriter = new BinaryWriter(p.StandardInput.BaseStream);
    inBinWriter.Write(PlainText);
    inBinWriter.Flush();
    inBinWriter.Close();
}
catch (Exception e)
{
    m_evt.WriteEntry("PGP Encrypt: Cannot Stream the Plain Text into PGP, " + m_pgpExecutable + " " + pgpEncryptCommand + ":" + e.ToString(), EventLogEntryType.Error);
    m_evt.WriteEntry(PlainText.Length.ToString(), EventLogEntryType.Error);
    throw new PGPException(PGPErrorCode.PGPProcessError, e.Message);
}

事件日志显示：

PGP Encrypt: Cannot Stream the Plain Text into PGP, pgp.exe :System.IO.IOException: The pipe has been ended.

at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.WriteCore(Byte[] buffer, Int32 offset, Int32 count)
   at PGPServer.PGPWrapper.doEncrypt(String UserName, String ChannelName, Byte[] PlainText, Byte[]& CipherText, String SenderName) in ...

我得到的全部，我不知道会发生什么，任何帮助都会受到赞赏！谢谢！