using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace MD5_Base64
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }
        //加密MD5
        private void btnMD5_Click(object sender, EventArgs e)
        {
            string str = txtString.Text;
           lblMD5Result.Text = UserMd5(str);
        }

      
        //加密Base64
        private void btnBase64_Click(object sender, EventArgs e)
        {
            lblBase64Result.Text = Base64(lblMD5Result.Text, true);
        }

        //解密Base64
        private void btnDecrypt_Click(object sender, EventArgs e)
        {
            lblDecryptResult.Text = Base64(txtEncode.Text,false);
        }

        #region 01MD5加密        
        public static string UserMd5(string str)
        {
            string cl = str;
            string pwd = "";
            MD5 md5 = MD5.Create();//实例化一个md5对像
            // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
            byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
            // 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
            for (int i = 0; i < s.Length; i++)
            {
                // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符 
                pwd = pwd + s[i].ToString("x2");

            }
            return pwd;
        } 
        #endregion

        #region 02Base64加密
        static public string Base64(string s, bool c)
        {
            if (c)
            {
                //加密
                return System.Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(s));
            }
            else
            {

                try
                {
                    //解密
                    return System.Text.Encoding.Default.GetString(System.Convert.FromBase64String(s));
                }
                catch (Exception exp)
                {
                    return exp.Message;
                }
            }
        }
        #endregion

        #region 03Base64解密
        /// <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);
        }
        #endregion
    }
}