On the second point.

I did watch Gong Jianwei's program:)

But I have read at least five other related codes, and I don't know if they are all imitating each other or really necessary. All I see is ...

if(m_ctrlComm。 GetPortOpen())

m_ctrlComm。 SetPortOpen(FALSE)；

m_ctrlComm。 SetCommPort( 1)； //select com 1.

This type. I didn't see the same routine as I thought, so I asked.

On the first point:

It was written in WINAPI232 in the early days, and I don't know how to use the event-driven method. I can only create more than 60 threads in turn, and the program seems a little unstable, so I have to use controls.