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); 
                } 
        } 
}