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 :(