using System;

using System.Runtime.InteropServices;

public static class NetTool

{

    [Flags]

    private enum ConnectionState

    {

        INTERNET_CONNECTION_MODEM = 0x1,

        INTERNET_CONNECTION_LAN = 0x2,

        INTERNET_CONNECTION_PROXY = 0x4,

        INTERNET_RAS_INSTALLED = 0x10,

        INTERNET_CONNECTION_OFFLINE = 0x20,

        INTERNET_CONNECTION_CONFIGURED = 0x40

     }

    [DllImport("wininet.dll", CharSet = CharSet.Auto)]

    static extern bool InternetGetConnectedState(ref ConnectionState lpdwFlags, int dwReserved);

    public static bool IsConnectedToInternet()

    {

        ConnectionState description = ;

        bool conn = InternetGetConnectedState(ref description, );

        return conn;

    }

}