C#类如下：
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace ConsoleApplication1
{
/// <summary>
/// 加解密类
/// </summary>
public class EncryptHelper
{

//构造一个对称算法
private SymmetricAlgorithm mCSP = new TripleDESCryptoServiceProvider();

#region 加密解密函数

/// <summary>
/// 字符串的加密
/// </summary>
/// <param name="Value">要加密的字符串</param>
/// <param name="sKey">密钥，必须32位</param>
/// <param name="sIV">向量，必须是12个字符</param>
/// <returns>加密后的字符串</returns>
public string EncryptString(string Value, string sKey,string sIV)
{
try
{
ICryptoTransform ct;
MemoryStream ms;
CryptoStream cs;
byte[] byt;
mCSP.Key = Convert.FromBase64String(sKey);
mCSP.IV = Convert.FromBase64String(sIV);
//指定加密的运算模式
mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
//获取或设置加密算法的填充模式
mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
ct = mCSP.CreateEncryptor(mCSP.Key, mCSP.IV);//创建加密对象
byt = Encoding.UTF8.GetBytes(Value);
ms = new MemoryStream();
cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
cs.Write(byt, 0, byt.Length);
cs.FlushFinalBlock();
cs.Close();

return Convert.ToBase64String(ms.ToArray());
}
catch (Exception ex)
{
//MessageBox.Show(ex.Message, "出现异常", MessageBoxButtons.OK, MessageBoxIcon.Warning);
return ("Error in Encrypting " + ex.Message);
}
}

/// <summary>
/// 解密字符串
/// </summary>
/// <param name="Value">加密后的字符串</param>
/// <param name="sKey">密钥，必须32位</param>
/// <param name="sIV">向量，必须是12个字符</param>
/// <returns>解密后的字符串</returns>
public string DecryptString(string Value, string sKey, string sIV)
{
try
{
ICryptoTransform ct;//加密转换运算
MemoryStream ms;//内存流
CryptoStream cs;//数据流连接到数据加密转换的流
byte[] byt;
//将3DES的密钥转换成byte
mCSP.Key = Convert.FromBase64String(sKey);
//将3DES的向量转换成byte
mCSP.IV = Convert.FromBase64String(sIV);
mCSP.Mode = System.Security.Cryptography.CipherMode.ECB;
mCSP.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
ct = mCSP.CreateDecryptor(mCSP.Key, mCSP.IV);//创建对称解密对象
byt = Convert.FromBase64String(Value);
ms = new MemoryStream();
cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
cs.Write(byt, 0, byt.Length);
cs.FlushFinalBlock();
cs.Close();

return Encoding.UTF8.GetString(ms.ToArray());
}
catch (Exception ex)
{
//MessageBox.Show(ex.Message, "出现异常", MessageBoxButtons.OK, MessageBoxIcon.Warning);
return ("Error in Decrypting " + ex.Message);
}
}

#endregion
}
}

调用方法如下：
复制代码 代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
EncryptHelper helper = new EncryptHelper();

//加密
string oldValue = "13800138000";
//加密后结果
//密钥,必须32位
string sKey = "qJzGEh6hESZDVJeCnFPGuxzaiB7NLQM5";
//向量，必须是12个字符
string sIV = "andyliu1234=";
//print
string newValue = helper.EncryptString(oldValue,sKey,sIV);
Console.WriteLine("加密后:"+ newValue);
//解密
string desValue = helper.DecryptString(newValue,sKey,sIV);
//
Console.WriteLine("解密后:"+ desValue);
Console.ReadLine();

}
}
}