用C#实现Base64处理，加密解密，编码解码

using System;
using System.Text;

namespace Common
{
/// <summary>
/// 实现Base64加密解密
/// 作者：周公
/// 时间：2007
/// </summary>
public sealed class Base64
{
/// <summary>
/// Base64加密
/// </summary>
/// <param name="codeName">加密采用的编码方式</param>
/// <param name="source">待加密的明文</param>
/// <returns></returns>
public static string EncodeBase64(Encoding encode, string source)
{
byte[] bytes = encode.GetBytes(source);
try
{
encode = Convert.ToBase64String(bytes);
}
catch
{
encode = source;
}
return encode;
}

/// <summary>
/// Base64加密，采用utf8编码方式加密
/// </summary>
/// <param name="source">待加密的明文</param>
/// <returns>加密后的字符串</returns>
public static string EncodeBase64(string source)
{
return EncodeBase64(Encoding.UTF8, source);
}

/// <summary>
/// Base64解密
/// </summary>
/// <param name="codeName">解密采用的编码方式，注意和加密时采用的方式一致</param>
/// <param name="result">待解密的密文</param>
/// <returns>解密后的字符串</returns>
public static string DecodeBase64(Encoding encode, string result)
{
string decode = "";
byte[] bytes = Convert.FromBase64String(result);
try
{
decode = encode.GetString(bytes);
}
catch
{
decode = result;
}
return decode;
}

/// <summary>
/// Base64解密，采用utf8编码方式解密
/// </summary>
/// <param name="result">待解密的密文</param>
/// <returns>解密后的字符串</returns>
public static string DecodeBase64(string result)
{
return DecodeBase64(Encoding.UTF8, result);
}
}
}