InternetConnection

public class InternetConnection
{
    /// <summary>
    /// Check if internetconnection is available
    /// </summary>
    /// <param name="lpdwFlags">Returns info about connection</param>
    /// <param name="dwReserved">Reserved pass 0 (default)</param>
    /// <returns></returns>
    [DllImport("wininet.dll", CharSet = CharSet.Auto)]
    private extern static bool InternetGetConnectedState(ref InternetConnectionState_e lpdwFlags, int dwReserved = 0);

    /// <summary>
    /// 
    /// </summary>
    /// <param name="lpszUrl">the url ex "http://www.google.se/"</param>
    /// <param name="dwFlags"></param>
    /// <param name="dwReserved">Reserved pass 0 (default)</param>
    /// <returns></returns>
    [DllImport("wininet.dll", SetLastError = true)]
    private static extern bool InternetCheckConnection(string lpszUrl, InternetCheckConnectionFlags dwFlags = InternetCheckConnectionFlags.FLAG_ICC_FORCE_CONNECTION, int dwReserved = 0);

    public bool CheckConnection(string url)
    {
        return InternetCheckConnection(url);
    }

    public InternetConnectionState_e GetConnectedState()
    {
        InternetConnectionState_e lpdwFlags = (InternetConnectionState_e) 0;
        InternetConnection.InternetGetConnectedState(ref lpdwFlags);
        return lpdwFlags;
    }

}

[Flags]
public enum InternetCheckConnectionFlags : int
{
    FLAG_ICC_FORCE_CONNECTION = 0x1
}

[Flags]
public enum InternetConnectionState_e : int
{
    INTERNET_CONNECTION_MODEM = 0x1,
    INTERNET_CONNECTION_LAN = 0x2,
    INTERNET_CONNECTION_PROXY = 0x4,
    INTERNET_RAS_INSTALLED = 0x10,
    INTERNET_CONNECTION_OFFLINE = 0x20,
    INTERNET_CONNECTION_CONFIGURED = 0x40
}

public class Tests
{
    [TestCase(@"https://www.google.com/", true)]
    [TestCase(@"https://www.akdsfgiayebcvi.com/",false)]
    public void CheckConnectionTest(string url, bool expected)
    {
        var actual = new InternetConnection().CheckConnection(url);
        Assert.AreEqual(expected,actual);
    }

    [Test]
    public void TestNameTest()
    {
        var internetConnectionStateE = new InternetConnection().GetConnectedState();
    }
}