高手们帮帮我，一个VB小问题 - VB / 基础类

Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.Settings = "9600,N,8,1"
MSComm1.PortOpen = True
MSComm1.InputMode = comInputModeBinary
MSComm1.RThreshold = 1
Dim a As Long
End Sub

Private Sub MSComm1_OnComm()
Dim BytesReceived() As Byte
  Dim buffer As String
  Dim HData As String
  Dim i As Integer
  Select Case MSComm1.CommEvent
  Case comEvReceive '接收十六进制数据。并以十六进制显示
  MSComm1.InputLen = 0
  buffer = MSComm1.Input '接收数据至字符串中
  BytesReceived() = buffer '将数据转入Byte数组中
  For i = 0 To UBound(BytesReceived) '显示结果以十六进制显示
  If Len(Hex(BytesReceived(i))) = 1 Then
  HData = HData & "0" & Hex(BytesReceived(i))
  Else
  HData = HData & Hex(BytesReceived(i))
  End If
  Text1.Text = HData
  '最后将结果后入Text1中
  MSComm1.OutBufferCount = 0 '清除发送缓冲区
  MSComm1.InBufferCount = 0 '清除接收缓冲区
  Next
  End Select
End Sub
这是我的程序，现在要采集数据，就是HData，怎么