的WebRequest和System.Net.WebException上404，慢？ [英] WebRequest and System.Net.WebException on 404, slow?

问题描述

我使用的是WebRequest的检查，如果存在一个网页或媒体（图像）。在我的GetResponse获得System.Net.WebException异常。我通过100链接跑，感觉像它会慢那么它应该。有没有办法不得到这个异常，或者这更妥善地处理？

 的静态公共BOOL CheckExist（字符串URL）
 {
 HttpWebRequest的WREQ = NULL; 
 HttpWebResponse wresp = NULL; 
布尔RET = FALSE; 
试
 {
 WREQ =（HttpWebRequest的）WebRequest.Create（URL）; 
 wreq.KeepAlive = TRUE; 
 wresp =（HttpWebResponse）wreq.GetResponse（）; 
 RET = TRUE; 
} 
赶上（System.Net.WebException）
 {
} 
终于
 {
如果（wresp！= NULL）
 wresp.Close（）; 
} 
返回RET; 
} 
  

解决方案

尝试设置

  wreq.Method =头; 
  

的

的KeepAlive行之后。如果您呼叫的网络服务器是足够聪明，会告诉它不返回任何正文内容应该节省一些时间。

I am using a WebRequest to check if a web page or media (image) exist. On GetResponse i get a System.Net.WebException exception. I ran through 100 links and it feels like its going slower then it should. Is there a way to not get this exception or handle this more gracefully?

    static public bool CheckExist(string url)
    {
        HttpWebRequest wreq = null;
        HttpWebResponse wresp = null;
        bool ret = false;
        try
        {
            wreq = (HttpWebRequest)WebRequest.Create(url);
            wreq.KeepAlive = true;
            wresp = (HttpWebResponse)wreq.GetResponse();
            ret = true;
        }
        catch (System.Net.WebException)
        {
        }
        finally
        {
            if (wresp != null)
                wresp.Close();
        }
        return ret;
    }

解决方案

Try setting

wreq.Method = "Head";

after the "KeepAlive" line. If the webserver you are calling is smart enough, that will tell it not to return any body contents which should save some time.

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