我刚开始尝试使用C#WebClient
。我所拥有的是下面的代码,它从网站获取html代码并将其写入.txt文件。我唯一的问题是有些网站要求您在使用网站之前接受cookie。这导致的不是将真实的网站html代码写入.txt文件,而是编写cookie popup html代码。
代码:
string downloadedString;
System.Net.WebClient client;
client = new System.Net.WebClient();
//"http://nl.wikipedia.org/wiki/Lijst_van_spelers_van_het_Nederlands_voetbalelftal"
downloadedString = client.DownloadString(textBox1.Text);
using (StreamWriter write = new StreamWriter("Data.txt"))
{
write.Write(downloadedString);
}
那么解决方案是什么?有人可以指引我走正确的道路吗?
答案 0 :(得分:26)
用法:
CookieContainer cookieJar = new CookieContainer();
cookieJar.Add(new Cookie("my_cookie", "cookie_value", "/", "mysite"));
CookieAwareWebClient client = new CookieAwareWebClient(cookieJar);
string response = client.DownloadString("http://example.com/response_with_cookie_only.php");
public class CookieAwareWebClient : WebClient
{
public CookieContainer CookieContainer { get; set; }
public Uri Uri { get; set; }
public CookieAwareWebClient()
: this(new CookieContainer())
{
}
public CookieAwareWebClient(CookieContainer cookies)
{
this.CookieContainer = cookies;
}
protected override WebRequest GetWebRequest(Uri address)
{
WebRequest request = base.GetWebRequest(address);
if (request is HttpWebRequest)
{
(request as HttpWebRequest).CookieContainer = this.CookieContainer;
}
HttpWebRequest httpRequest = (HttpWebRequest)request;
httpRequest.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
return httpRequest;
}
protected override WebResponse GetWebResponse(WebRequest request)
{
WebResponse response = base.GetWebResponse(request);
String setCookieHeader = response.Headers[HttpResponseHeader.SetCookie];
//do something if needed to parse out the cookie.
if (setCookieHeader != null)
{
Cookie cookie = new Cookie(); //create cookie
this.CookieContainer.Add(cookie);
}
return response;
}
}
您将看到GetWebRequest和GetWebResponse的两个重写方法。可以重写这些方法来处理cookie容器。
答案 1 :(得分:4)
只需将标题中的cookie字符串存储到本地会话_cookies字符串
中if (System.Web.HttpContext.Current.Session["cookie"] != null)
_cookies = System.Web.HttpContext.Current.Session["cookie"].ToString();
using (WebClient wc = new WebClient())
{
wc.Headers.Add("Cookie", _cookies);
string HtmlResult = wc.UploadString(bridge_url, myParameters);
_cookies = wc.ResponseHeaders["Set-Cookie"];
Debug.WriteLine("Headers" + _cookies);
System.Web.HttpContext.Current.Session["cookie"] = _cookies;
}
答案 2 :(得分:2)
这可能与How can I get the WebClient to use Cookies?
密切相关我上面提到的问题是针对VB.NET的,但C#的机制应该是相同的。我怀疑你看到的行为是网站正在发送一个cookie然后再请求它,但你的客户端没有设置将cookie返回给服务器,所以它解释为你不接受cookie。'
您是否使用像Fiddler这样的分析工具来分析与客户沟通的内容?
您可能还必须发送特定的HTTP标头以表明您接受Cookie,但我不记得在我过去的经历中需要它。