在YuebonCore快速开发框架开源项目中涉及到当前登录用户登录IP是否被禁止登录访问系统，获取登录IP后怎么去判断过滤呢？我们采用将IP地址转为Int32数字型，然后去判断大小。
Sql Server IP地址转int型
cast(replace(StartIP,'.','') as bigint)
获取当前用户IP地址字符串转int型
int ipv = ip.Replace(".","").ToInt();
综合起来方法如下:
/// <summary>
/// 验证IP地址是否被拒绝
/// </summary>
/// <param name="ip"></param>
/// <returns></returns>
public bool ValidateIP(string ip)
{
long ipv = ip.Replace(".", "").ToLong();
string where = " (cast(replace(StartIP,'.','') as bigint)>=" + ipv + " and cast(replace(EndIP,'.','') as bigint)<=" + ipv + ") and FilterType=0 and EnabledMark=1";
int count = GetCountByWhere(where);
return count > 0 ? true : false;
}
