说的检测注册表发 只能测到可用串口 并不能检测到正在用的串口号呀
http://zhidao.baidu.com/link?url=6H1XHgeLTlErvKLX8Ey-lDbuS_58hM3Hb_kOUyqatBeK6FftS__Vtqm9bJG7Jtd1-KCMCi1HWwgeWzXhAXh28GlZfrDUOiWquGutIlKE9mi