//得到其静态方法创建的MD5对象

             MD5 md5 = MD5.Create();

             //要加密的字符串

             string str="";

             //字节数组

             byte[] strbuffer = Encoding.Default.GetBytes(str);

             //加密并返回字节数组

             strbuffer= md5.ComputeHash(strbuffer);

             string strNew = "";

             foreach (byte item in strbuffer)

             {

                 //对字节数组中元素格式化后拼接

                 strNew+=item.ToString("x2");

             }

             Console.WriteLine(strNew);