C#中用于Java DES加密的等效代码？

using System;
using System.Security.Cryptography;
using System.Text;

public class DESHelper
{
    public static string Encrypt(string plainText, string key, string iv)
    {
        byte[] keyBytes = Encoding.UTF8.GetBytes(key);
        byte[] ivBytes = Encoding.UTF8.GetBytes(iv);
        byte[] plainBytes = Encoding.UTF8.GetBytes(plainText);

        using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
        {
            des.Key = keyBytes;
            des.IV = ivBytes;
            des.Mode = CipherMode.CBC;
            des.Padding = PaddingMode.PKCS7;

            using (ICryptoTransform encryptor = des.CreateEncryptor())
            {
                byte[] encryptedBytes = encryptor.TransformFinalBlock(plainBytes, 0, plainBytes.Length);
                return Convert.ToBase64String(encryptedBytes);
            }
        }
    }

    public static string Decrypt(string encryptedText, string key, string iv)
    {
        byte[] keyBytes = Encoding.UTF8.GetBytes(key);
        byte[] ivBytes = Encoding.UTF8.GetBytes(iv);
        byte[] encryptedBytes = Convert.FromBase64String(encryptedText);

        using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
        {
            des.Key = keyBytes;
            des.IV = ivBytes;
            des.Mode = CipherMode.CBC;
            des.Padding = PaddingMode.PKCS7;

            using (ICryptoTransform decryptor = des.CreateDecryptor())
            {
                byte[] decryptedBytes = decryptor.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
                return Encoding.UTF8.GetString(decryptedBytes);
            }
        }
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        string plainText = "Hello, World!";
        string key = "12345678";
        string iv = "87654321";

        string encryptedText = DESHelper.Encrypt(plainText, key, iv);
        Console.WriteLine("Encrypted Text: " + encryptedText);

        string decryptedText = DESHelper.Decrypt(encryptedText, key, iv);
        Console.WriteLine("Decrypted Text: " + decryptedText);
    }
}