Instance member cannot be used on type in closures

Question

I have a class like

class Main
{
var manager: IOHIDManager
var connectedDeviceList = [String]()
init()
{
    manager = IOHIDManagerCreate(kCFAllocatorDefault, IOOptionBits(kIOHIDOptionsTypeNone))
    IOHIDManagerSetDeviceMatching(manager, nil)
    IOHIDManagerRegisterDeviceMatchingCallback(manager, Handle_DeviceMatchingCallback, nil)
}
func Handle_DeviceMatchingCallback(_ context: UnsafeMutableRawPointer?, _ result: IOReturn, _ sender: UnsafeMutableRawPointer?, _ device: IOHIDDevice)
{
    connectedDeviceList.append(String(describing: device))
    print("Connected")
    connectedData() // just another function
}
}

I get an error A C function pointer can only be formed from a reference to a 'func' or a literal closure

So I tried to write in closures like

let Handle_DeviceMatchingCallback: IOHIDDeviceCallback = {context, result, sender, device in
    connectedDeviceList.append(String(describing: device))
    print("Connected")
    connectedData()
}

Now I get Instance member cannot be used on type 'Main' on connectedData() and connectedDeviceList

When I remove those instance variable and method, there is no error but I need to implement that method.

How can I solve this?