blocks|key|324691|text|是。我的意思是，重写GetWebRequest()是解决WebClient有限功能的最佳方案。在我知道这个选项之前，我在HttpWebRequest层写了很多非常痛苦的代码，因为WebClient几乎(但不完全)做了我需要的事情。派生要容易得多。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|324692|另一种选择是使用常规的WebClient类，但是在发出请求之前手动填充Cookie头，然后在响应上拉出Set-+Cookie头。CookieContainer类上有一些帮助程序方法，可以使创建和解析这些头文件变得更容易:分别是CookieContainer.SetCookies()和CookieContainer.GetCookieHeader()。|offset|length|style|CODE|324693|我更喜欢前一种方法，因为它对调用者来说更容易，并且比第二种方法需要更少的重复代码。此外，派生方法对于多个可扩展性场景(例如cookies、代理等)也是以相同的方式工作的。|324694|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.net.cookiecontainer.setcookies.aspx|1|http://msdn.microsoft.com/en-us/library/system.net.cookiecontainer.getcookieheader.aspx^0|0|35|S|3Y|X|35|S|0|3Y|X|1|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@$D|V|E|W|F|G]|$D|X|E|Y|F|G]]|9|@$D|Z|E|10|1|11]|$D|12|E|13|1|14]]|A|$]]|$1|H|3|I|5|6|7|15|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]|R|$5|M|N|O|A|$P|S]]]]

Yes. IMHO, overriding GetWebRequest() is the best solution to WebClient's limited functionalty. Before I knew about this option, I wrote lots of really painful code at the HttpWebRequest layer because WebClient almost, but not quite, did what I needed. Derivation is much easier. 

Another option is to use the regular WebClient class, but manually populate the Cookie header before making the request and then pull out the Set-Cookies header on the response. There are helper methods on the CookieContainer class which make creating and parsing these headers easier: <a href="http://msdn.microsoft.com/en-us/library/system.net.cookiecontainer.setcookies.aspx" rel="noreferrer"><code>CookieContainer.SetCookies()</code></a> and <a href="http://msdn.microsoft.com/en-us/library/system.net.cookiecontainer.getcookieheader.aspx" rel="noreferrer"><code>CookieContainer.GetCookieHeader()</code></a>, respectively. 

I prefer the former approach since it's easier for the caller and requires less repetitive code than the second option. Also, the derivation approach works the same way for multiple extensibility scenarios (e.g. cookies, proxies, etc.).

blocks|key|327662|text|+WebClient+wb+=+new+WebClient();
+wb.Headers.Add(HttpRequestHeader.Cookie,+"somecookie");|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|327663|来自评论的|unstyled|327664|如何格式化cookie的名称和值来代替"somecookie“？|offset|length|style|BOLD|327665|wb.Headers.Add(HttpRequestHeader.Cookie,+"cookiename=cookievalue");+|327666|对于多个cookies：|327667|wb.Headers.Add(HttpRequestHeader.Cookie,+
++++++++++++++"cookiename1=cookievalue1;"+%2B
++++++++++++++"cookiename2=cookievalue2");|327668|entityMap^0|0|0|0|W|0|0|0|C|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|V|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|W|8|@$I|X|J|Y|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$B|C]]|$1|O|3|P|5|F|7|10|8|@$I|11|J|12|K|L]]|9|@]|A|$]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$B|C]]|$1|S|3|-4|5|F|7|14|8|@]|9|@]|A|$]]]|T|$]]

<pre><code> WebClient wb = new WebClient();
 wb.Headers.Add(HttpRequestHeader.Cookie, "somecookie");
</code></pre>

From Comments

How do you format the name and value of the cookie in place of "somecookie" ?

<pre><code>wb.Headers.Add(HttpRequestHeader.Cookie, "cookiename=cookievalue"); 
</code></pre>

For multiple cookies: 

<pre><code>wb.Headers.Add(HttpRequestHeader.Cookie, 
 "cookiename1=cookievalue1;" +
 "cookiename2=cookievalue2");
</code></pre>

blocks|key|3291366|text|这篇文章只是你找到的文章的延伸。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3291367|public+class+WebClientEx+:+WebClient
{
++++public+WebClientEx(CookieContainer+container)
++++{
++++++++this.container+=+container;
++++}

++++public+CookieContainer+CookieContainer
++++++++{
++++++++++++get+{+return+container;+}
++++++++++++set+{+container=+value;+}
++++++++}

++++private+CookieContainer+container+=+new+CookieContainer();

++++protected+override+WebRequest+GetWebRequest(Uri+address)
++++{
++++++++WebRequest+r+=+base.GetWebRequest(address);
++++++++var+request+=+r+as+HttpWebRequest;
++++++++if+(request+!=+null)
++++++++{
++++++++++++request.CookieContainer+=+container;
++++++++}
++++++++return+r;
++++}

++++protected+override+WebResponse+GetWebResponse(WebRequest+request,+IAsyncResult+result)
++++{
++++++++WebResponse+response+=+base.GetWebResponse(request,+result);
++++++++ReadCookies(response);
++++++++return+response;
++++}

++++protected+override+WebResponse+GetWebResponse(WebRequest+request)
++++{
++++++++WebResponse+response+=+base.GetWebResponse(request);
++++++++ReadCookies(response);
++++++++return+response;
++++}

++++private+void+ReadCookies(WebResponse+r)
++++{
++++++++var+response+=+r+as+HttpWebResponse;
++++++++if+(response+!=+null)
++++++++{
++++++++++++CookieCollection+cookies+=+response.Cookies;
++++++++++++container.Add(cookies);
++++++++}
++++}
}|code-block|syntax|javascript|3291368|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This one is just extension of article you found.

<pre><code>
public class WebClientEx : WebClient
{
 public WebClientEx(CookieContainer container)
 {
 this.container = container;
 }

 public CookieContainer CookieContainer
 {
 get { return container; }
 set { container= value; }
 }

 private CookieContainer container = new CookieContainer();

 protected override WebRequest GetWebRequest(Uri address)
 {
 WebRequest r = base.GetWebRequest(address);
 var request = r as HttpWebRequest;
 if (request != null)
 {
 request.CookieContainer = container;
 }
 return r;
 }

 protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result)
 {
 WebResponse response = base.GetWebResponse(request, result);
 ReadCookies(response);
 return response;
 }

 protected override WebResponse GetWebResponse(WebRequest request)
 {
 WebResponse response = base.GetWebResponse(request);
 ReadCookies(response);
 return response;
 }

 private void ReadCookies(WebResponse r)
 {
 var response = r as HttpWebResponse;
 if (response != null)
 {
 CookieCollection cookies = response.Cookies;
 container.Add(cookies);
 }
 }
}
</code></pre>

blocks|key|3077967|text|我认为有一种更简洁的方法，你不需要创建新的way客户端(它也可以与第三方库一起工作)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3077968|internal+static+class+MyWebRequestCreator
{
++++private+static+IWebRequestCreate+myCreator;

++++public+static+IWebRequestCreate+MyHttp
++++{
++++++++get
++++++++{
++++++++++++if+(myCreator+==+null)
++++++++++++{
++++++++++++++++myCreator+=+new+MyHttpRequestCreator();
++++++++++++}
++++++++++++return+myCreator;
++++++++}
++++}

++++private+class+MyHttpRequestCreator+:+IWebRequestCreate
++++{
++++++++public+WebRequest+Create(Uri+uri)
++++++++{
++++++++++++var+req+=+System.Net.WebRequest.CreateHttp(uri);
++++++++++++req.CookieContainer+=+new+CookieContainer();
++++++++++++return+req;
++++++++}
++++}
}|code-block|syntax|javascript|3077969|现在你要做的就是选择你想要使用的域名：|3077970|++++WebRequest.RegisterPrefix("http://example.com/",+MyWebRequestCreator.MyHttp);|3077971|这意味着发往example.com的任何webrequest现在都将使用您的自定义webrequest创建器，包括标准的webclient。这种方法意味着你不必接触所有的代码。您只需调用寄存器前缀一次，就可以完成它。你也可以注册"http“前缀来选择任何地方的任何东西。|3077972|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I think there's cleaner way where you don't have to create a new webclient (and it'll work with 3rd party libraries as well)

<pre><code>internal static class MyWebRequestCreator
{
 private static IWebRequestCreate myCreator;

 public static IWebRequestCreate MyHttp
 {
 get
 {
 if (myCreator == null)
 {
 myCreator = new MyHttpRequestCreator();
 }
 return myCreator;
 }
 }

 private class MyHttpRequestCreator : IWebRequestCreate
 {
 public WebRequest Create(Uri uri)
 {
 var req = System.Net.WebRequest.CreateHttp(uri);
 req.CookieContainer = new CookieContainer();
 return req;
 }
 }
}
</code></pre>

Now all you have to do is opt in for which domains you want to use this:

<pre><code> WebRequest.RegisterPrefix("http://example.com/", MyWebRequestCreator.MyHttp);
</code></pre>

That means ANY webrequest that goes to example.com will now use your custom webrequest creator, including the standard webclient. This approach means you don't have to touch all you code. You just call the register prefix once and be done with it.
You can also register for "http" prefix to opt in for everything everywhere.

blocks|key|327690|text|HttpWebRequest修改分配给它的CookieContainer。不需要处理返回的cookie。只需将cookie容器分配给每个web请求即可。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|327691|public+class+CookieAwareWebClient+:+WebClient
{
++++public+CookieContainer+CookieContainer+{+get;+set;+}+=+new+CookieContainer();

++++protected+override+WebRequest+GetWebRequest(Uri+uri)
++++{
++++++++WebRequest+request+=+base.GetWebRequest(uri);
++++++++if+(request+is+HttpWebRequest)
++++++++{
++++++++++++(request+as+HttpWebRequest).CookieContainer+=+CookieContainer;
++++++++}
++++++++return+request;
++++}
}|code-block|syntax|javascript|327692|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The HttpWebRequest modifies the CookieContainer assigned to it. There is no need to process returned cookies. Simply assign your cookie container to every web request.

<pre><code>public class CookieAwareWebClient : WebClient
{
 public CookieContainer CookieContainer { get; set; } = new CookieContainer();

 protected override WebRequest GetWebRequest(Uri uri)
 {
 WebRequest request = base.GetWebRequest(uri);
 if (request is HttpWebRequest)
 {
 (request as HttpWebRequest).CookieContainer = CookieContainer;
 }
 return request;
 }
}
</code></pre>

I've previously used a CookieContainer with HttpWebRequest and HttpWebResponse sessions, but now, I want to use it with a WebClient. As far as I understand, there is no built-in method like there is for HttpWebRequests (<code>request.CookieContainer</code>). How can I collect cookies from a WebClient in a CookieContainer?

I <a href="http://www.google.com/search?rlz=1C1GGLS_enUS308US308&amp;sourceid=chrome&amp;ie=UTF-8&amp;q=webclient.cookiecontainer" rel="noreferrer">googled</a> for this and found <a href="http://couldbedone.blogspot.com/2007/08/webclient-handling-cookies.html" rel="noreferrer">the following sample</a>:

<pre><code>public class CookieAwareWebClient : WebClient
{
 private readonly CookieContainer m_container = new CookieContainer();

 protected override WebRequest GetWebRequest(Uri address)
 {
 WebRequest request = base.GetWebRequest(address);
 HttpWebRequest webRequest = request as HttpWebRequest;
 if (webRequest != null)
 {
 webRequest.CookieContainer = m_container;
 }
 return request;
 }
}
</code></pre>

Is this the best way to do it?

Using CookieContainer with WebClient class

我以前将CookieContainer与HttpWebRequest和HttpWebResponse会话一起使用，但现在，我想将其与WebClient一起使用。据我所知，没有像HttpWebRequests (request.CookieContainer)那样的内置方法。如何从CookieContainer中的Web...

问在WebClient类中使用CookieContainer
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