C# 批量生成随机密码必须包含数字和字母并用加密算法加密

static void Main(string[] args)
    {
      string chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
      Random randrom = new Random((int)DateTime.Now.Ticks);
      string path1 = @"C:\Users\lenovo\Desktop\pws.txt";
      for (int j = 0; j < 10000;j++ )
      {
        string str = "";
        for (int i = 0; i < 8; i++)
        {
          str += chars[randrom.Next(chars.Length)];//randrom.Next(int i)返回一个小于所指定最大值的非负随机数
        }
        if (IsNumber(str))//判断是否全是数字
          continue;
        if (IsLetter(str))//判断是否全是字母
          continue;
        File.AppendAllText(path1, str);
        string pws = Md5(str,32);//MD5加密
        File.AppendAllText(path1, "," + pws + "\r\n");
      }
      Console.WriteLine("ok");
      Console.Read();
    }

 //判断是否全是数字
    static bool IsNumber(string str)
    {
      if (str.Trim("0123456789".ToCharArray()) == "")
        return true;
      return false;
    }
    //判断是否全是字母
    static bool IsLetter(string str)
    {
      if (str.Trim("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".ToCharArray()) == "")
        return true;
      return false;
    }

/// <summary>
    /// MD5加密
    /// </summary>
    /// <param name="str">加密字元</param>
    /// <param name="code">加密位数16/32</param>
    /// <returns></returns>
    public static string Md5(string str, int code)
    {
      string strEncrypt = string.Empty;
      MD5 md5 = new MD5CryptoServiceProvider();
      byte[] fromData = Encoding.GetEncoding("GB2312").GetBytes(str);
      byte[] targetData = md5.ComputeHash(fromData);
      for (int i = 0; i < targetData.Length; i++)
      {
        strEncrypt += targetData[i].ToString("X2");
      }
      if (code == 16)
      {
        strEncrypt = strEncrypt.Substring(8, 16);
      }
      return strEncrypt;
    }