public static string ComputeMD5 (string text) // 计算字符串的 MD5
{
System.Security.Cryptography.MD5CryptoServiceProvider md = new System.Security.Cryptography.MD5CryptoServiceProvider();
string hc = BitConverter.ToString(md.ComputeHash(Encoding.Default.GetBytes(text)));
md.Dispose();
return (hc);
}