请帮忙看一下用API写的串口模块问题出在哪，不能发送和接收

'发送数据
Public Function SendData(bytBuffer() As Byte, lngSize As Long) As Long
Dim m As Integer
  On Error GoTo ToExit '打开错误陷阱
  '------------------------------------------------
  If (m_Handle = 0) Then
  SendData = 1
  Exit Function
  End If

  Dim dwBytesWritten As Long
  Dim bWriteStat As Long
  Dim ComStats As ComStat
  Dim dwErrorFlags As Long

  dwBytesWritten = lngSize

  Call ClearCommError(m_Handle, dwErrorFlags, ComStats)
  bWriteStat = WriteFile(m_Handle, bytBuffer(0), lngSize, dwBytesWritten, m_OverlappedWrite)
  If bWriteStat = 0 Then
  If GetLastError() = ERROR_IO_PENDING Then
  Call GetOverlappedResult(m_Handle, m_OverlappedWrite, dwBytesWritten, 1) '等待直到发送完毕
  End If
  Else
  dwBytesWritten = 0
  End If

  SendData = dwBytesWritten
  '------------------------------------------------
  Exit Function
  '----------------
ToExit:
  SendData = -1
End Function

'读取数据
Public Function ReadData(bytBuffer() As Byte, lngSize As Long, Optional Overtime As Long = 3000) As Long
  On Error GoTo ToExit '打开错误陷阱
  '------------------------------------------------
  If (m_Handle = 0) Then
  ReadData = 1
  Exit Function
  End If

  Dim lngBytesRead As Long
  Dim fReadStat As Long
  Dim dwRes As Long

  lngBytesRead = lngSize

  '读数据
  fReadStat = ReadFile(m_Handle, bytBuffer(0), lngSize, lngBytesRead, m_OverlappedRead)
  If fReadStat = 0 Then
  If GetLastError() = ERROR_IO_PENDING Then '重叠 I/O 操作在进行中
  dwRes = WaitForSingleObject(m_OverlappedRead.hEvent, Overtime) '等待，直到超时
  Select Case dwRes
  Case WAIT_OBJECT_0: '读完成
  If GetOverlappedResult(m_Handle, m_OverlappedRead, lngBytesRead, 0) = 0 Then
  '错误
  ReadData = -2
  Exit Function
  End If
  Case WAIT_TIMEOUT: '超时
  ReadData = -1
  Exit Function
  Case Else: 'WaitForSingleObject 错误
  End Select
  End If
  End If
  ReadData = lngBytesRead
  '------------------------------------------------
  Exit Function
  '----------------
ToExit:
  ReadData = -1
End Function

楼主，你把你的代码传到资源中，大家下来看看，这样看累！

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