//计算字符串的MD5值 public string GetMD5(string sDataIn) { MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); byte[] bytValue, bytHash; bytValue = System.Text.Encoding.UTF8.GetBytes(sDataIn); bytHash = md5.ComputeHash(bytValue); md5.Clear(); string sTemp = ""; for (int i = 0; i < bytHash.Length; i++) { sTemp += bytHash[i].ToString("X").PadLeft(2, '0'); } return sTemp.ToLower(); } //计算文件的MD5值 public string MD5Value(String filepath) { MD5 md5 = new MD5CryptoServiceProvider(); byte[] md5ch; using (FileStream fs = File.OpenRead(filepath)) { md5ch = md5.ComputeHash(fs); } md5.Clear(); string strMd5 = ""; for (int i = 0; i < md5ch.Length - 1; i++) { strMd5 += md5ch[i].ToString("x").PadLeft(2, '0'); } return strMd5; }