Can't query from Win32_VolumeChangeEvent

[qwerty22121998]

type Win32_VolumeChangeEvent struct {
	EventType uint16
	DriveName string
}

func main() {
	var dst []Win32_VolumeChangeEvent
	q := wmi.CreateQuery(&dst, "")
	fmt.Println(q)

	for {
		err := wmi.Query(q, &dst)
		if err != nil {
			log.Fatal(err)
		}
		if len(dst) == 0 {
			continue
		}
		for _, v := range dst {
			fmt.Println(v)
		}

	}
}

but the result always be empty. when the example run well, i don't know why :(