public void IsAddressible(Uri uri, IsAddressibleCallback callback, object userToken)
 {
     using (var client = new MyClient())
     {
         client.HeadOnly = true;
         client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(IsAddressibleHeadString);
         client.DownloadStringAsync(uri, new object[] { callback, userToken });
     }
 }
 public bool IsAddressible(Uri uri)
 {
     try
     {
         using (var client = new MyClient())
         {
             client.HeadOnly = true;
             client.DownloadString(uri);
             return(true);
         }
     }
     catch (Exception loi)
     {
     }
     return(false);
 }
        public bool IsAddressible(Uri uri)
        {
            try
            {
                using (var client = new MyClient())
                {
                    client.HeadOnly = true;
                    client.DownloadString(uri);
                    return true;
                }
            }
            catch (Exception loi)
            {

            }
            return false;
        }