Question

我正在使用带有cookie的WebClient类，如下所述：Using CookieContainer with WebClient class

将自定义用户代理添加到此WebClient发出的每个请求中需要执行哪些步骤？

我试着把

Headers.Add(HttpRequestHeader.UserAgent, "...")

进入

protected override WebRequest GetWebRequest

但这不起作用：“必须使用适当的属性修改此标头”。

Answer 1

来自http://msdn.microsoft.com/en-us/library/system.net.webclient.aspx，

using System;
using System.Net;
using System.IO;

    public class Test
    {
        public static void Main (string[] args)
        {
            if (args == null || args.Length == 0)
            {
                throw new ApplicationException ("Specify the URI of the resource to retrieve.");
            }
            WebClient client = new WebClient ();

            // Add a user agent header in case the 
            // requested URI contains a query.

            client.Headers.Add ("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");

            Stream data = client.OpenRead (args[0]);
            StreamReader reader = new StreamReader (data);
            string s = reader.ReadToEnd ();
            Console.WriteLine (s);
            data.Close ();
            reader.Close ();
        }
    }

Answer 2

有点迟到的答案，但在这里;我遇到了和你一样的问题，并通过在你链接的例子中添加一行来解决它：

public class CookieAwareWebClient : WebClient
{
    private CookieContainer m_container = new CookieContainer();

    protected override WebRequest GetWebRequest(Uri address)
    {
        WebRequest request = base.GetWebRequest(address);
        if (request is HttpWebRequest)
        {
            (request as HttpWebRequest).UserAgent       = "CUSTOM USERAGENT HERE";
            (request as HttpWebRequest).CookieContainer = m_container;
        }
        return request;
    }
}

webclient标题类

2 个答案: