如何在foreach中重试try/catch语句

本文关键字：try catch 语句 重试 foreach | 更新日期: 2023-09-27 18:02:41

请看这个帖子:

在这个线程中，我们回答了关于do...while的相同问题。那么foreach呢?这意味着我们如何在foreach内用另一个代理(proxy_line_num的另一个整数)重试try/catch中的try语句:

foreach (string link_1 in links_with_kid)
{
   try
   {
      getData = "";
      req = (HttpWebRequest)WebRequest.Create(link_1);
      req.Method = "GET";
      req.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
      req.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:19.0) Gecko/20100101 Firefox/19.0";
      req.ContentType = "text/html; charset=utf-8";
      req.Referer = "http://www.example.com/";
      req.KeepAlive = true;
      req.Timeout = 25000;
      if (useproxy)
      {
         string[] Ok_ip_port_ar = list_lines_GPL[proxy_line_num].Split(':');
         proxy_line_num++;
         if (proxy_line_num == list_lines_GPL.Count)
         {
            proxy_line_num = 0;
         }
         proxy = new WebProxy(Ok_ip_port_ar[0], int.Parse(Ok_ip_port_ar[1]));
       }
       req.Proxy = proxy;
       req.CookieContainer = cookieJar1;
       res = (HttpWebResponse)req.GetResponse();
       Stream = res.GetResponseStream();
       reader = new StreamReader(Stream);
       reader_str = reader.ReadToEnd();
       htmlDoc = new HtmlAgilityPack.HtmlDocument();
       htmlDoc.LoadHtml(reader_str);
       var images = from image in htmlDoc.DocumentNode.Descendants("img")
                             select image;
       string address = string.Empty;
       foreach (var image in images)
       {
          if (image.Attributes["src"] != null)
          {
             string[] address_ar = image.Attributes["src"].Value.Split('/');
             string address_ar_last = address_ar[address_ar.Length - 1];
             char[] address_ar_last_char = address_ar_last.ToCharArray();
             if (address_ar_last_char.Length == 8
                            &&
                            Char.IsUpper(address_ar_last_char[0])
                            &&
                            Char.IsUpper(address_ar_last_char[1])
                            &&
                            Char.IsUpper(address_ar_last_char[2])
                            &&
                            Char.IsUpper(address_ar_last_char[3]))
             {
                address = image.Attributes["src"].Value;
                string localFilename = @"c:'images-from-istgah'" + address_ar_last;
                using (WebClient client = new WebClient())
                {
                   client.DownloadFile(address, localFilename);
                }
             }
           }
         }
      }
      catch (Exception ex)
      {
      }
         reader.Close();
         Stream.Close();
         res.Close();
 }

如何在foreach中重试try/catch语句

我不认为你可以用一个foreach。它的目的是为你提供迭代器中的下一项。

如果我是你，我会使用普通的for循环和迭代器。这样你就可以控制何时进入下一个项目。

编辑:

写的时候，while在c#中更有意义

IEnumerator<String> iter = list.GetEnumerator();
bool bHasMore = iter.MoveNext();
while (bHasMore) {
  try {
    ...
    bHasMore = Iter.MoveNext();
  }
  catch ...
}

我脑子里没有完整的参考资料，所以你可能需要查找一些东西来编译它，但我希望不是。

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