C# 獲取頁面的響應時間

HttpWebRequest 請求：

DateTime start_time = DateTime.Now;

            try
            {
                HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create("訪問地址");
                HttpWebResponse webresponse = (HttpWebResponse)webrequest.GetResponse();
                if (webresponse.StatusCode == HttpStatusCode.OK)
                {
                    DateTime end_time = DateTime.Now;
                    TimeSpan ts = end_time - start_time;
                    int ch = (int)ts.TotalMilliseconds;//響應時間.(毫秒)
        	 }
            }

用WebBrowser打開：

爲WebBrowser添加Navigating和DocumentCompleted事件.
分別在兩個方法中記錄當前時間.最後用DocumentCompleted-Navigating的時間差即爲響應時間