.NET 图片解密为BASE64

#region 图片加密
       /// <summary>
       /// 加密本地文件
       /// </summary>
       /// <param name="inputname">读取文件的路径</param>
       /// <param name="outname">要输出的文件路径</param>
       /// <param name="key">密钥</param>
       /// <returns></returns>
       public bool EncrptFile(string inputname, string outname, string key = "R4yqHaM%")
       {
           //通过des加密
           DESCryptoServiceProvider des = new DESCryptoServiceProvider();
           //通过流打开文件
           FileStream fs = System.IO.File.OpenRead(inputname);
           //获取文件二进制字符
           byte[] inputByteArray = new byte[fs.Length];
           //读流文件
           fs.Read(inputByteArray, 0, (int)fs.Length);
           //关闭流
           fs.Close();
           //获得加密字符串二进制字符
           byte[] keyByteArray = Encoding.Default.GetBytes(key);
           //计算指定字节组指定区域哈希值
           SHA1 ha = new SHA1Managed();
           byte[] hb = ha.ComputeHash(keyByteArray);
           //加密密钥数组
           byte[] sKey = new byte[8];
           //加密变量
           byte[] sIV = new byte[8];
           for (int i = 0; i < 8; i++)
               sKey[i] = hb[i];
           for (int i = 8; i < 16; i++)
               sIV[i - 8] = hb[i];
           //获取加密密钥
           des.Key = sKey;
           //设置加密初始化向量
           des.IV = sIV;
           MemoryStream ms = new MemoryStream();
           CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
           cs.Write(inputByteArray, 0, inputByteArray.Length);
           cs.FlushFinalBlock();
           fs = System.IO.File.OpenWrite(outname);
           foreach (byte b in ms.ToArray())
           {
               fs.WriteByte(b);
           }
           fs.Close();
           cs.Close();
           ms.Close();
           return true;
       }


       #endregion

       #region 图片解密
       /// <summary>
       /// 解密图片 返回一个base64
       /// </summary>
       /// <param name="filename"></param>
       /// <param name="key"></param>
       /// <returns></returns>
       public string ReadEnImage(string filename, string key = "R4yqHaM%")
       {
           //通过des解密
           DESCryptoServiceProvider des = new DESCryptoServiceProvider();

           //通过流读取文件
           FileStream fs = File.OpenRead(this.FilePath.Text);
           //获取文件二进制字符
           byte[] inputByteArray = new byte[fs.Length];
           //读取流文件
           fs.Read(inputByteArray, 0, (int)fs.Length);
           //关闭流
           fs.Close();
           //密钥数组
           byte[] keyByteArray = Encoding.Default.GetBytes("R4yqHaM%");
           //定义哈希变量
           SHA1 ha = new SHA1Managed();
           //计算指定字节组指定区域哈希值
           byte[] hb = ha.ComputeHash(keyByteArray);
           //加密密钥数组
           byte[] sKey = new byte[8];
           //加密变量
           byte[] sIV = new byte[8];
           for (int i = 0; i < 8; i++)
               sKey[i] = hb[i];
           for (int i = 8; i < 16; i++)
               sIV[i - 8] = hb[i];
           //获取加密密钥
           des.Key = sKey;
           //加密变量
           des.IV = sIV;
           MemoryStream ms = new MemoryStream();
           CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
           cs.Write(inputByteArray, 0, inputByteArray.Length);
           cs.FlushFinalBlock();
           byte[] by = ms.ToArray();
           string base64 = Convert.ToBase64String(by);
           fs.Close();
           cs.Close();
           ms.Close();
           return "data:image/png;base64," + base64;

       }

       #endregion

说明：加密代码为将图片加密后存储了一份，如果需要删除加密前的图片  自行修改代码

解密部分为  在解密后返回的不是一个图片  而是一个base64   这是我在web开发项目中遇到的问题所要求的。希望能帮助你，谢谢支持！