判断一个IP区间（或IP）是否被另一个IP区间所包含

using System;
 using System.Text.RegularExpressions;
namespace HKH.Common
 {
  /// <summary>
  /// clsMacAndIP 的摘要说明。
  /// </summary>
  public class clsIPAddress
  {
   private clsIPAddress()
   {
   }
  #region 判断是否合法 IP
  /// <summary>
   /// 判断是否合法 IP
   /// </summary>
   /// <param name="strIP"></param>
   /// <returns></returns>
   public static bool ValidateIPAddress(string strIP)
   {
    if ( null == strIP || "" == strIP.Trim() || Convert.IsDBNull(strIP) )
     return false;
   return Regex.IsMatch(strIP,@"^((/d{1,2}|1/d/d|2[0-4]/d|25[0-5])/.){3}(/d{1,2}|1/d/d|2[0-4]/d|25[0-5])$");
   }
  #endregion
  #region 转换成数值
  /// <summary>
   ///  转换为数值
   /// </summary>
   /// <param name="IPAddr"></param>
   /// <returns></returns>
   public static uint TransNum(string IPAddr)
   {
    if ( !ValidateIPAddress(IPAddr) )
     throw new Exception("IP Address isn't Well Format!");
   string[] IPStrArray = new string[4];
    IPStrArray = IPAddr.Split('.');
    return MAKELONG(MAKEWORD(byte.Parse(IPStrArray[3]),byte.Parse(IPStrArray[2])),MAKEWORD(byte.Parse(IPStrArray[1]),byte.Parse(IPStrArray[0])));
   }
  #endregion
  #region 格式化
  /// <summary>
   /// 格式化
   /// </summary>
   /// <param name="IPAddr"></param>
   /// <returns></returns>
   public static string Format(string IPAddr)
   {
    if (IPAddr[0] == '.')
     IPAddr = "0" + IPAddr;
   if (IPAddr[IPAddr.Length - 1] == '.')
     IPAddr += "0.0.0.";
    else
     IPAddr += ".0.0.0.";
   IPAddr = IPAddr.Substring(0,clsString.IndexOf(IPAddr,".",4));
//   //去掉无用的0
 //   IPAddr = Regex.Replace(IPAddr,"^0{1,2}","");
 //   IPAddr = Regex.Replace(IPAddr,@"/.+0{1,2}",".");
   if ( ValidateIPAddress(IPAddr) )
     return IPAddr;
   return "0.0.0.0";
   }
  #endregion
  #region 比较两个IP的大小
  /// <summary>
   /// 比较两个IP的大小
   /// </summary>
   /// <param name="IP1"></param>
   /// <param name="IP2"></param>
   /// <returns></returns>
   public static int Compare(string IP1,string IP2)
   {
    if ( !(ValidateIPAddress(IP1) && ValidateIPAddress(IP2)))
     throw new Exception("IP Address isn't Well Format!");
   uint IPNum1 = TransNum(IP1);
    uint IPNum2 = TransNum(IP2);
   if (IPNum1 == IPNum2 )
     return 0;
   return IPNum1 > IPNum2 ? 1 : -1 ;
   }
  #endregion
  #region 判断一个IP是否包含在指定IP区间内
  /// <summary>
   /// 判断一个IP是否包含在指定IP区间内
   /// </summary>
   /// <param name="IPRegion"></param>
   /// <param name="IP"></param>
   /// <returns></returns>
   public static bool IsInclude(string[] IPRegion,string IP)
   {
    //验证
    if ( null == IPRegion || null == IP || 0 == IPRegion.Length )
     return false;
   if ( !ValidateIPAddress(IP) )
     return false;
   if ( 1 == IPRegion.Length )
    {
     if ( !ValidateIPAddress(IPRegion[0]) )
      return false;
 
     if ( 0 == Compare(IPRegion[0],IP) )
      return true;
    }
   if ( !(ValidateIPAddress(IPRegion[0]) && ValidateIPAddress(IPRegion[1])) )
     return false;
   uint IPNum = TransNum(IP);
    uint IPNum1 = TransNum(IPRegion[0]);
    uint IPNum2 = TransNum(IPRegion[1]);
   //比较
    if ( Math.Min(IPNum1,IPNum2) <= IPNum && Math.Max(IPNum1,IPNum2) >= IPNum )
     return true;
 
    return false;
   }
  #endregion
  #region 判断两个IP区间是否重叠，重叠则返回合并区间，否则返回 NULL
  /// <summary>
   /// 判断两个IP区间是否重叠，重叠则返回合并区间，否则返回 NULL
   /// </summary>
   /// <param name="IPRegion1"></param>
   /// <param name="IPRegion2"></param>
   /// <returns></returns>
   public static string[] CheckOverlapAndMerge(string[] IPRegion1,string[] IPRegion2)
   {
    //验证
    if ( null == IPRegion1 || null == IPRegion2 || 0 == IPRegion1.Length || 0 == IPRegion2.Length )
     return null;
   //分数组长度进行处理 =1 和 > 1
    if ( 1 == IPRegion1.Length )
    {
     if (!ValidateIPAddress(IPRegion1[0]))
      throw new Exception("IP Address isn't Well Format!");
    if ( 1 == IPRegion2.Length )
     {
      if (!ValidateIPAddress(IPRegion2[0]))
       throw new Exception("IP Address isn't Well Format!");
 
      //相等
      if ( Equals(IPRegion1[0],IPRegion2[0]) )
       return IPRegion1;
     }
     // > 1
     else
     {
      if ( !(ValidateIPAddress(IPRegion2[0]) && ValidateIPAddress(IPRegion2[1])) )
       throw new Exception("IP Address isn't Well Format!");
 
      if ( IsInclude(IPRegion2,IPRegion1[0]) )
       return IPRegion2;
     }
    }
    // >1
    else
    {
     if ( !(ValidateIPAddress(IPRegion1[0]) && ValidateIPAddress(IPRegion1[1])) )
      throw new Exception("IP Address isn't Well Format!");
    if ( 1 == IPRegion2.Length )
     {
      if (!ValidateIPAddress(IPRegion2[0]))
       throw new Exception("IP Address isn't Well Format!");
 
      if ( IsInclude(IPRegion1,IPRegion2[0]) )
       return IPRegion1;
     }
     // > 1
     else
     {
      if ( !(ValidateIPAddress(IPRegion2[0]) && ValidateIPAddress(IPRegion2[1])) )
       throw new Exception("IP Address isn't Well Format!");
 
      uint IPNum1_1 = TransNum(IPRegion1[0]);
      uint IPNum1_2 = TransNum(IPRegion1[1]);
      uint IPNum2_1 = TransNum(IPRegion2[0]);
      uint IPNum2_2 = TransNum(IPRegion2[1]);
 
      #region 大小格式整理 IP[0] <= IP[1]
     if ( IPNum1_1 > IPNum1_2 )
      {
       string stemp = IPRegion1[0];
       IPRegion1[0] = IPRegion1[1];
       IPRegion1[1] = stemp;
      uint utemp = IPNum1_1;
       IPNum1_1 = IPNum1_2;
       IPNum1_2 = utemp;
      }
     if ( IPNum2_1 > IPNum2_2 )
      {
       string stemp = IPRegion2[0];
       IPRegion2[0] = IPRegion2[1];
       IPRegion2[1] = stemp;
      uint utemp = IPNum2_1;
       IPNum2_1 = IPNum2_2;
       IPNum2_2 = utemp;
      }
     #endregion
     #region 判断合并
     //互不包含
      if ( IPNum1_1 > IPNum2_2 || IPNum1_2 < IPNum2_1 )
       return null;
     //合并
      string[] result = new string[2];
     result[0] = IPNum1_1 < IPNum2_1 ? IPRegion1[0] : IPRegion2[0] ;
      result[1] = IPNum1_2 > IPNum2_2 ? IPRegion1[1] : IPRegion2[1] ;
     return result;
     #endregion
     }
   }
   return null;
   }
  #endregion
  #region 私有方法
  /// <summary>
   /// 移位转换_8
   /// </summary>
   /// <param name="bLow"></param>
   /// <param name="bHigh"></param>
   /// <returns></returns>
   private static ushort MAKEWORD(byte bLow,byte bHigh)
   {
    return ((ushort) (((byte) (bLow)) | ((ushort) ((byte) (bHigh))) << 8));
   }
  /// <summary>
   /// 移位转换_16
   /// </summary>
   /// <param name="bLow"></param>
   /// <param name="bHigh"></param>
   /// <returns></returns>
   private static uint MAKELONG(ushort bLow,ushort bHigh)
   {
    return ((uint) (((ushort) (bLow)) | ((uint) ((ushort) (bHigh))) << 16));
   }
 
   #endregion
  }
 }