C AES CBC mode encryption and decryption

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            String encrypt = Encrypt("lw112190 Test information ");
            Console.WriteLine(encrypt);

            String decrypt = Decrypt(encrypt);
            Console.WriteLine(decrypt);

            Console.ReadKey();

        }

        static string key = "1234567890abcdef";
        static string IV = "1234567890abcdef";

        /// <summary>  
        /// AES encryption 
        /// </summary>  
        /// <param name="encryptStr"> Plaintext </param>  
        /// <returns></returns>
        static private string Encrypt(string encryptStr)
        {
            var _aes = new AesCryptoServiceProvider();
            _aes.BlockSize = 128;
            _aes.KeySize = 256;
            _aes.Key = Encoding.UTF8.GetBytes(key);
            _aes.IV = Encoding.UTF8.GetBytes(IV);
            _aes.Padding = PaddingMode.PKCS7;
            _aes.Mode = CipherMode.CBC;
            var _crypto = _aes.CreateEncryptor(_aes.Key, _aes.IV);
            byte[] encrypted = _crypto.TransformFinalBlock(Encoding.UTF8.GetBytes(encryptStr), 0, Encoding.UTF8.GetBytes(encryptStr).Length);
            _crypto.Dispose();
            return System.Convert.ToBase64String(encrypted);
        }

        /// <summary>  
        /// AES Decrypt 
        /// </summary>  
        /// <param name="decryptStr"> Ciphertext </param>  
        /// <returns></returns>  
        static private string Decrypt(string decryptStr)
        {
            var _aes = new AesCryptoServiceProvider();
            _aes.BlockSize = 128;
            _aes.KeySize = 256;
            _aes.Key = Encoding.UTF8.GetBytes(key);
            _aes.IV = Encoding.UTF8.GetBytes(IV);
            _aes.Padding = PaddingMode.PKCS7;
            _aes.Mode = CipherMode.CBC;
            var _crypto = _aes.CreateDecryptor(_aes.Key, _aes.IV);
            byte[] decrypted = _crypto.TransformFinalBlock(System.Convert.FromBase64String(decryptStr), 0, System.Convert.FromBase64String(decryptStr).Length);
            _crypto.Dispose();
            return Encoding.UTF8.GetString(decrypted);
        }
    }
}