请教高手：如何判断本机是否已经和InterNet连通？谢谢！！

Question

如何判断本机是否已经和InterNet连通？谢谢！！

Answer 1

Code说话的例子：
void On_Timer()
{
    try
    {
        // Create an HTTP Web request
        // to an Uri that's always available.
        HttpWebRequest request = (HttpWebRequest) 
           HttpWebRequest.Create("www.google.com");        // Perform GET
        HttpWebResponse response = 
           (HttpWebResponse) request.GetResponse();
        if (HttpStatusCode.OK == response.StatusCode)
        {
            // HTTP = 200, close the request and return true
            response.Close();
            e.Result = true;
        }
        else
        {
            // Other status; return false
            e.Result = false;
        }
    }
    catch (WebException)
    {
        // Deffinitely offline
        e.Result = false;
    }
}

Answer 2

catch(System.Net.WebException ee)
{
MessageBox.Show("请确认与互联网相连接");
}

Answer 3

[DllImport("wininet.dll")] 
private extern static bool InternetGetConnectedState(out int Description,int ReservedValue); public static bool IsConnectedToInternet() 
{ 
int Desc=0; 
return InternetGetConnectedState(out Desc,0) ; 
} 
Another method
public string NetStatus()
                {
                        ManagementObjectCollection objects;
                        string status = "";
                        ManagementObjectSearcher searcher = new ManagementObjectSearcher();
                        searcher.Query.QueryString = "Select * From Win32_NetworkAdapter ";
                        objects = searcher.Get();
                        foreach(ManagementObject obj in objects)
                        {
                                foreach(PropertyData p in obj.Properties)
                                {
                                        if(p.Name.Equals("NetConnectionStatus"))
                                        {
                                                if(p.Value!=null)
                                                {
                                                        status = p.Value.ToString();
                                                }
                                        }
                                }
                        }
                        switch(status)
                        {
                                case "0":
                                        return "Disconnected";
                                case "1":
                                        return "Connecting ...";
                                case "2":
                                        return "Connected";
                                case "3":
                                        return "Disconnecting ...";
                                case "4":
                                        return "Hardware not present";
                                case "5":
                                        return "Hardware disabled";
                                case "6":
                                        return "Hardware malfunction";
                                case "7":
                                        return "Media disconnected";
                                case "8":
                                        return "Authenticating";
                                case "9":
                                        return "Authentication succeeded";
                                case "10":
                                        return "Authentication failed";
                                default:
                                        return "";
                        }
                }