[c#] 네트워크 연결을 어떻게 확인합니까?

표시된 대답은 100 % 괜찮지 만 표준 방법이 가상 카드 (가상 상자, …)에 속는 경우가 있습니다. 또한 속도 (직렬 포트, 모뎀 등)에 따라 일부 네트워크 인터페이스를 폐기하는 것이 바람직합니다.

다음은 이러한 경우를 확인하는 코드입니다.

    /// <summary>
    /// Indicates whether any network connection is available
    /// Filter connections below a specified speed, as well as virtual network cards.
    /// </summary>
    /// <returns>
    ///     <c>true</c> if a network connection is available; otherwise, <c>false</c>.
    /// </returns>
    public static bool IsNetworkAvailable()
    {
        return IsNetworkAvailable(0);
    }

    /// <summary>
    /// Indicates whether any network connection is available.
    /// Filter connections below a specified speed, as well as virtual network cards.
    /// </summary>
    /// <param name="minimumSpeed">The minimum speed required. Passing 0 will not filter connection using speed.</param>
    /// <returns>
    ///     <c>true</c> if a network connection is available; otherwise, <c>false</c>.
    /// </returns>
    public static bool IsNetworkAvailable(long minimumSpeed)
    {
        if (!NetworkInterface.GetIsNetworkAvailable())
            return false;

        foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
        {
            // discard because of standard reasons
            if ((ni.OperationalStatus != OperationalStatus.Up) ||
                (ni.NetworkInterfaceType == NetworkInterfaceType.Loopback) ||
                (ni.NetworkInterfaceType == NetworkInterfaceType.Tunnel))
                continue;

            // this allow to filter modems, serial, etc.
            // I use 10000000 as a minimum speed for most cases
            if (ni.Speed < minimumSpeed)
                continue;

            // discard virtual cards (virtual box, virtual pc, etc.)
            if ((ni.Description.IndexOf("virtual", StringComparison.OrdinalIgnoreCase) >= 0) ||
                (ni.Name.IndexOf("virtual", StringComparison.OrdinalIgnoreCase) >= 0))
                continue;

            // discard "Microsoft Loopback Adapter", it will not show as NetworkInterfaceType.Loopback but as Ethernet Card.
            if (ni.Description.Equals("Microsoft Loopback Adapter", StringComparison.OrdinalIgnoreCase))
                continue;

            return true;
        }
        return false;
    }

답변

public static bool IsConnectedToInternet()
        {
            bool returnValue = false;
            try
            {

                int Desc;
                returnValue = Utility.InternetGetConnectedState(out Desc, 0);
            }
            catch
            {
                returnValue = false;
            }
            return returnValue;
        }

[DllImport("wininet.dll")]
        public extern static bool InternetGetConnectedState(out int Description, int ReservedValue);