如何将ISO8601 TimeSpan转换为C# TimeSpan？

using System;
using System.Globalization;

public class Program
{
    public static void Main()
    {
        string iso8601TimeSpan = "P1DT2H30M";
        TimeSpan result = ParseIso8601TimeSpan(iso8601TimeSpan);
        
        Console.WriteLine($"Days: {result.Days}");
        Console.WriteLine($"Hours: {result.Hours}");
        Console.WriteLine($"Minutes: {result.Minutes}");
        Console.WriteLine($"Seconds: {result.Seconds}");
        Console.WriteLine($"Milliseconds: {result.Milliseconds}");
    }

    public static TimeSpan ParseIso8601TimeSpan(string iso8601TimeSpan)
    {
        if (string.IsNullOrEmpty(iso8601TimeSpan))
            throw new ArgumentException("ISO 8601 TimeSpan string cannot be null or empty.");

        // Remove the 'P' and 'T' characters
        string[] parts = iso8601TimeSpan.Replace("P", "").Replace("T", "").Split(new char[] { 'D', 'H', 'M', 'S' }, StringSplitOptions.RemoveEmptyEntries);

        int days = 0, hours = 0, minutes = 0, seconds = 0;

        foreach (string part in parts)
        {
            if (part.EndsWith("D"))
            {
                days = int.Parse(part.Replace("D", ""));
            }
            else if (part.EndsWith("H"))
            {
                hours = int.Parse(part.Replace("H", ""));
            }
            else if (part.EndsWith("M"))
            {
                minutes = int.Parse(part.Replace("M", ""));
            }
            else if (part.EndsWith("S"))
            {
                seconds = int.Parse(part.Replace("S", ""));
            }
        }

        return new TimeSpan(days, hours, minutes, seconds);
    }
}

public static bool IsValidIso8601TimeSpan(string iso8601TimeSpan)
{
    if (string.IsNullOrEmpty(iso8601TimeSpan))
        return false;

    var regex = new System.Text.RegularExpressions.Regex(@"^P(\d+D)?(T(\d+H)?(\d+M)?(\d+(\.\d+)S)?)?$");
    return regex.IsMatch(iso8601TimeSpan);
}

try
{
    days = int.Parse(part.Replace("D", ""));
}
catch (FormatException)
{
    throw new FormatException("Invalid format for days in ISO 8601 TimeSpan.");
}