C# 43. 获取UDP可用端口

//返回  0：失败   startPort~endPort：成功
private int FindNextAvailableUDPPort(int startPort, int endPort)
{
    int port = startPort;
    bool isAvailable = true;

        IPGlobalProperties ipGlobalProperties =
            IPGlobalProperties.GetIPGlobalProperties();
        IPEndPoint[] endPoints =
            ipGlobalProperties.GetActiveUdpListeners();

        do
        {
            if (!isAvailable)
            {
                port++;
                isAvailable = true;
            }

            foreach (IPEndPoint endPoint in endPoints)
            {
                if (endPoint.Port != port)
                    continue;
                isAvailable = false;
                break;
            }

        } while (!isAvailable && port <= endPort);
        if (isAvailable == true)
        {
            return port;
        }
        else
        {
            return 0;
        }
}