How to check if COM port is disconnected

[sneiksus]

Greeting, is there a way to check that USB cable was unpluged? isOpened property always return true even when the usb cable was physically disconnected?

[FengChendian]

isOpened property just reflects user code states in dart. So it's true if the usb cable was physically disconnected.

I know you want isOpened to automatically become false when cable disconnected. It needs WNDPROC callback function in winuser.h And may be multi-thread? I didn't implement this function because I don't know how dart implements win32 system callback function. 😭 Maybe win32 package supports this function now. I will try it.

Now, there are some other solutions to check USB COM PORT connection status:

1. Using getAvailablePorts function to compare lists
2. try write bytes or read bytes, and catch exception
3. try close and reopen it