檢測WebService是否存在

若是不用組件，能夠用下列方法：

     public bool IsWebServiceAvaiable(String url)        {            try            {                HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(url);                using(HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse())                {                    return true;                }            }            catch (WebException e)            {                if (e.Status == WebExceptionStatus.ProtocolError)                {                   XXX.LogMessage(String.Format("Status Code : {0}", ((HttpWebResponse)e.Response).StatusCode));                    XXXX.LogMessage(String.Format("Status Description : {0}", ((HttpWebResponse)e.Response).StatusDescription));                }            }            catch (Exception e)            {              XXX.LogMessage(e.Message);            }            return false;        }