golang生成随机字符串

func GetRoundName(size int) string {
    str := "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    bytes := []byte(str)
    result := []byte{}
    r := rand.New(rand.NewSource(time.Now().UnixNano()))
    for i := 0; i < size; i++ {
        result = append(result, bytes[r.Intn(len(bytes))])
    }
    return string(result)
}