IP地址转数字

public long IPToNumber(string ip)
{
	string[] arrayIP = ip.Split('.');
	long sip1 = long.Parse(arrayIP[0]);
	long sip2 = long.Parse(arrayIP[1]);
	long sip3 = long.Parse(arrayIP[2]);
	long sip4 = long.Parse(arrayIP[3]);
	long ipNum = sip1 * 256 * 256 * 256 + sip2 * 256 * 256 + sip3 * 256 + sip4;
	return ipNum;
}

数字转IP地址

public string NumberToIP(long ipNum)
{
	StringBuilder builder = new StringBuilder();
	builder.Append((ipNum >> 24) & 0xFF).Append(".");
	builder.Append((ipNum >> 16) & 0xFF).Append(".");
	builder.Append((ipNum >> 8) & 0xFF).Append(".");
	builder.Append(ipNum & 0xFF);
	return builder.ToString();
}