问从自定义验证属性中访问ErrorMessage

EN

[IsDateBeforeFixedDate(4, 0, 0, ErrorMessage = "*The departure date should be between 4 days and 11 months")]

  public sealed class IsDateBeforeFixedDateAttribute : ValidationAttribute, IClientValidatable
  {

    public IsDateBeforeFixedDateAttribute(int days, int months, int years) : base(days, months, years)
    {
      //I want to read the ErrorMessage string here! (i.e. "*The departure date should be between 4 days and 11 months")
    }
  }