GUID 相关操作（如发现新方法会一直更新）

/// <summary>  
/// 根据GUID获取16位的唯一字符串  
/// </summary>   /// <param name=\"guid\"></param>  /// <returns></returns>  public static string GuidTo16String() { long i = 1; foreach (byte b in Guid.NewGuid().ToByteArray()) i *= ((int)b + 1); return string.Format(\"{0:x}\", i - DateTime.Now.Ticks); } /// <summary>  /// 根据GUID获取19位的唯一数字序列  /// </summary>  /// <returns></returns>  public static long GuidToLongID() { byte[] buffer = Guid.NewGuid().ToByteArray(); return BitConverter.ToInt64(buffer, 0); }