检查Internet连接状态

我想通过c#检查Internet连接.我的计算机已与Network连接，仅Internet禁用.如何查找Internet连接状态.
以下代码不适合我的要求.即使仅连接了网络且已禁用Internet，它也会返回true.

I want to check the internet connectivity thro c#.My computer is connected with Network only internet is disabled.How do i find the internet connectivity status.
The following code is not suitable for my requirement.it returns true even only network is connected and internet disabled.

[DllImport("wininet.dll")]
  private extern static bool InternetGetConnectedState( out int Description, int ReservedValue );
  public static bool IsConnectedToInternet( )
  {
    int Desc ;
    return InternetGetConnectedState( out Desc, 0 ) ;
  }

此(以下)代码有效，但会花费更多时间并使我的应用程序挂起，

This(following) code works but takes more time and makes my application hangs,

System.Net.HttpWebRequest req = (System.Net.HttpWebRequest)System.Net.WebRequest.Create("http://www.google.com");
                req.Method = "HEAD";

                System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)req.GetResponse();
                resp.Close(); return true;

还有其他检查互联网连接状态的好方法.

Is any other good way to check internet connectivity status.
All your Suggestions are appreciable!!!