如果我已经有正则表达式作为c＃属性的数据属性，我是否需要stringlength

Question

我在下面有这个。似乎正则表达式就足够了，但不确定吗？

    [Required(ErrorMessage = "Routing is required")]
    [StringLength(9, MinimumLength = 9, ErrorMessage = "Your routing number must be 9 digits")]
    [RegularExpression(@"^\d{9}$", ErrorMessage = "Routing number must be 9 digits. 0-9")]
    public string Routing { get; set; }