做了个TCP侦听的程序，当获取数据后，对数据进行一个字一个字的读取，然后转换成十六进制，发现，当大于7F时，进来的就是FFFD，而不是80，并且总是在此处出错，请高手指教。相关代码如下：
            Dim a As String = ""
            While Listening '循环获取数据
                If isConnected = True Then
                   Try
                        Message = ""
                       Dim Reader As New StreamReader(tpClient.GetStream())
                        While Reader.Peek() >= 0
                            a = Hex(Reader.Read())
                            Message = Message & Microsoft.VisualBasic.Right("00" & a, 2) & " "
                        End While
                         Message = Trim(Message)
                         If Len(Message) > 2 Then
                             showMessage = Message
                             Me.demoThread = New Thread(New ThreadStart(AddressOf Me.ThreadProcSafe))
                             Me.demoThread.Start()
                         End If
                     Catch ex As Exception
                         isConnected = False
                         Thread.CurrentThread.Abort()
                         'MsgBox("连接错误。")
                     End Try
                 End If
             End While
怎么样才能处理大于7F的数据，谢谢了！！

自己提出的问题，自己解决，这儿人气不行哦：
        While Listening
            Try
                Message = ""
                Dim Reader As NetworkStream = tpClient.GetStream()
                If Reader.CanRead Then
                    StreamDataNumber = tpClient.Available
                    ReDim bytes(StreamDataNumber - 1)
                    Reader.Read(bytes, 0, StreamDataNumber)
                    For i = 0 To StreamDataNumber - 1
                        Message = Message & Microsoft.VisualBasic.Right("00" & Hex(bytes(i)), 2)
                    Next
                End If
        End While