如何从RegularExpressionAttribute中提取正则表达式？

using System;
using System.ComponentModel.DataAnnotations;
using System.Reflection;

public class MyClass
{
    [RegularExpression(@"^\d{4}-\d{2}-\d{2}$")]
    public string Date { get; set; }
}

public class Program
{
    public static void Main()
    {
        PropertyInfo propertyInfo = typeof(MyClass).GetProperty("Date");
        RegularExpressionAttribute attribute = (RegularExpressionAttribute)propertyInfo.GetCustomAttribute(typeof(RegularExpressionAttribute));
        
        if (attribute != null)
        {
            string regexPattern = attribute.Pattern;
            Console.WriteLine("提取到的正则表达式为：" + regexPattern);
        }
    }
}