判断IP地址是否为内网IP地址

///   <summary> 
///  判断IP地址是否为内网IP地址
///   </summary> 
///   <param name="ipAddress"> IP地址字符串 </param> 
///   <returns></returns> 
private   bool  IsInnerIP(String ipAddress)
{
     bool  isInnerIp  =   false ;
     long  ipNum  =  GetIpNum(ipAddress);
     /* *
       私有IP：A类  10.0.0.0-10.255.255.255
               B类  172.16.0.0-172.31.255.255
               C类  192.168.0.0-192.168.255.255
               当然，还有127这个网段是环回地址   
      * */ 
     long  aBegin  =  GetIpNum( " 10.0.0.0 " );
     long  aEnd  =  GetIpNum( " 10.255.255.255 " );
     long  bBegin  =  GetIpNum( " 172.16.0.0 " );
     long  bEnd  =  GetIpNum( " 172.31.255.255 " );
     long  cBegin  =  GetIpNum( " 192.168.0.0 " );
     long  cEnd  =  GetIpNum( " 192.168.255.255 " );
    isInnerIp  =  IsInner(ipNum, aBegin, aEnd)  ||  IsInner(ipNum, bBegin, bEnd)  ||  IsInner(ipNum, cBegin, cEnd)  ||  ipAddress.Equals( " 127.0.0.1 " );
     return  isInnerIp;
}
///   <summary> 
///  把IP地址转换为Long型数字
///   </summary> 
///   <param name="ipAddress"> IP地址字符串 </param> 
///   <returns></returns> 
private   long  GetIpNum(String ipAddress)
{
    String[] ip  =  ipAddress.Split( ' . ' );
     long  a  =   int .Parse(ip[ 0 ]);
     long  b  =   int .Parse(ip[ 1 ]);
     long  c  =   int .Parse(ip[ 2 ]);
     long  d  =   int .Parse(ip[ 3 ]);

     long  ipNum  =  a  *   256   *   256   *   256   +  b  *   256   *   256   +  c  *   256   +  d;
     return  ipNum;
}
///   <summary> 
///  判断用户IP地址转换为Long型后是否在内网IP地址所在范围
///   </summary> 
///   <param name="userIp"></param> 
///   <param name="begin"></param> 
///   <param name="end"></param> 
///   <returns></returns> 
private   bool  IsInner( long  userIp,  long  begin,  long  end)
{
     return  (userIp  >=  begin)  &&  (userIp  <=  end);
}