判斷有幾個可用的ＣＯＭ口

      '判斷有幾個可用的ＣＯＭ口
    Public Function getComNames() As String()
        Dim Reg As Microsoft.Win32.RegistryKey  '定義一個操作向
        Dim strName As String()  '定義一個名稱的集合
        Dim com As String()   '定義一個com口的數組
        Reg = Registry.LocalMachine
        Reg = Reg.OpenSubKey("hardware/devicemap/serialcomm", True) '定義爲機器硬件
        strName = Reg.GetValueNames()  '得到名稱
        ReDim com(Reg.ValueCount)
        For i As Integer = 0 To Reg.ValueCount - 1
            com(i) = Reg.GetValue(strName(i))  '得到ＣＯＭ口
        Next
        Reg.Close()
        Return com           '返回
    End Function