[C#] 计算大文件的MD5的两种方式(直接调用方法计算，流计算-适用于大文件)

来源：互联网发布：vmware网络配置文件编辑：程序博客网时间：2024/06/05 04:11

通过.NET中的默认类实现，但是采用不同类，针对不同的情况：

具体如下：

类：

/// <summary>    /// 文件MD5操作类    /// </summary>    public class MD5Checker    {        /// <summary>        /// 通过MD5CryptoServiceProvider类中的ComputeHash方法直接传入一个FileStream类实现计算MD5        /// 操作简单，代码少，调用即可        /// </summary>        /// <param name="path">文件地址</param>        /// <returns>MD5Hash</returns>        public static string getMD5ByMD5CryptoService(string path)        {            if (!File.Exists(path))                throw new ArgumentException(string.Format("<{0}>, 不存在", path));            FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);            MD5CryptoServiceProvider md5Provider = new MD5CryptoServiceProvider();            byte[] buffer = md5Provider.ComputeHash(fs);            string resule = BitConverter.ToString(buffer);            resule = resule.Replace("-", "");            md5Provider.Clear();            fs.Close();            return resule;        }        /// <summary>        /// 通过HashAlgorithm的TransformBlock方法对流进行叠加运算获得MD5        /// 实现稍微复杂，但可使用与传输文件或接收文件时同步计算MD5值        /// 可自定义缓冲区大小，计算速度较快        /// </summary>        /// <param name="path">文件地址</param>        /// <returns>MD5Hash</returns>        public static string getMD5ByHashAlgorithm(string path)        {            if (!File.Exists(path))                throw new ArgumentException(string.Format("<{0}>, 不存在", path));            int bufferSize = 1024 * 16;//自定义缓冲区大小16K            byte[] buffer = new byte[bufferSize];            Stream inputStream = File.Open(path, FileMode.Open, FileAccess.Read, FileShare.Read);            HashAlgorithm hashAlgorithm = new MD5CryptoServiceProvider();            int readLength = 0;//每次读取长度            var output = new byte[bufferSize];            while ((readLength = inputStream.Read(buffer, 0, buffer.Length)) > 0)            {                //计算MD5                hashAlgorithm.TransformBlock(buffer, 0, readLength, output, 0);            }            //完成最后计算，必须调用(由于上一部循环已经完成所有运算，所以调用此方法时后面的两个参数都为0)            hashAlgorithm.TransformFinalBlock(buffer, 0, 0);            string md5 = BitConverter.ToString(hashAlgorithm.Hash);                        hashAlgorithm.Clear();            inputStream.Close();            md5 = md5.Replace("-", "");            return md5;        }    }

测试：

static void Main(string[] args)        {            Console.WriteLine("第一种方式:");            Console.WriteLine(DateTime.Now.Ticks);            Console.WriteLine(DateTime.Now.ToString());            Console.WriteLine(MD5Checker.getMD5ByMD5CryptoService(@"D:\ShareFiles\Softwares\Office2013.zip"));            Console.WriteLine(DateTime.Now.Ticks);            Console.WriteLine(DateTime.Now.ToString());            Console.WriteLine("第二种方式:");            Console.WriteLine(DateTime.Now.Ticks);            Console.WriteLine(DateTime.Now.ToString());            Console.WriteLine(MD5Checker.getMD5ByHashAlgorithm(@"D:\ShareFiles\Softwares\Office2013.zip"));            Console.WriteLine(DateTime.Now.Ticks);            Console.WriteLine(DateTime.Now.ToString());            Console.ReadKey();        }

结果：

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