Question

I am using .NET, C# and WPF, and I need to check whether the connection is opened to a certain URL, and I can’t get any code to work that I have found on the Internet.

I tried:

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
    IAsyncResult result = socket.BeginConnect("localhost/myfolder/", 80, null, null);
    bool success = result.AsyncWaitHandle.WaitOne(3000, true);
    if (!success)
    {
        MessageBox.Show("Web Service is down!");
    }
    else
        MessageBox.Show("Everything seems ok");
}
finally
{
    socket.Close();
}

But I always get the message that everything is OK even if I shut down my local Apache server.

I also tried:

ing ping = new Ping();
PingReply reply;
try
{
    reply = ping.Send("localhost/myfolder/");
    if (reply.Status != IPStatus.Success)
        MessageBox.Show("The Internet connection is down!");
    else
        MessageBox.Show("Seems OK");
}
catch (Exception ex)
{
    MessageBox.Show("Error: " + ex.Message);
}

But this always gives an exception (ping seems to work only pinging the server, so localhost works but localhost/myfolder/ doesnt)

Please how to check the connection so it would work for me?

Answer 1

In the end I used my own code:

private bool CheckConnection(String URL)
{
    try
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
        request.Timeout = 5000;
        request.Credentials = CredentialCache.DefaultNetworkCredentials;
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();

        if (response.StatusCode == HttpStatusCode.OK)
            return true;
        else
            return false;
    }
    catch
    {
        return false;
    }
}

An interesting thing is that when the server is down (I turn off my Apache) I’m not getting any HTTP status, but an exception is thrown. But this works good enough 🙂