如何用visual basic6编写代码来检测串口的连接或断开？

Private Sub CheckSerialPortConnection()
    Dim comPort As String
    Dim portOpen As Boolean
    
    ' 设置要检测的串口号
    comPort = "COM1"
    
    ' 尝试打开串口
    On Error Resume Next
    MSComm1.CommPort = comPort
    MSComm1.Settings = "9600,N,8,1"
    MSComm1.PortOpen = True
    
    ' 检查串口是否成功打开
    If Err.Number = 0 Then
        portOpen = True
        MSComm1.PortOpen = False ' 关闭串口
    Else
        portOpen = False
    End If
    
    ' 显示结果
    If portOpen Then
        MsgBox "串口 " & comPort & " 已连接"
    Else
        MsgBox "串口 " & comPort & " 未连接"
    End If
End Sub