c#的代码判断用户ip是否在指定的ip段内

/// <summary>
/// 检测用户ip是否在指定的ip段中
/// </summary>
/// <param name="ip">用户ip</param>
/// <param name="begip">起始ip</param>
/// <param name="endip">结束ip</param>
/// <returns></returns>
protected bool isinip(string ip, string begip, string endip)
{
int[] inip, begipint, endipint = new int[4];
inip = getIp(ip);
begipint = getIp(begip);
endipint = getIp(endip);
for (int i = 0; i < 4; i++)
{
if (inip[i] < begipint[i] || inip[i] > endipint[i])
{
return false;
}
else if (inip[i] > begipint[i] || inip[i] < endipint[i])
{
return true;
}
}
return true;
}

/// <summary>
/// 将ip地址转成整形数组
/// </summary>
/// <param name="ip"></param>
/// <returns></returns>
protected int[] getIp(string ip)
{
int[] retip = new int[4];
int i, count;
char c;
for (i = 0, count = 0; i < ip.Length; i++)
{
c = ip[i];
if (c != '.')
{
retip[count] = retip[count] * 10 + int.Parse(c.ToString());
}
else
{
count++;
}
}

return retip;

}