虚拟用户 XXX 下载文件时登录

Question

I am using WebClient class for downloading files from a given URL. I am using following function to save it on local server,

WebClient wb = new WebClient();
NetworkCredential creds = new NetworkCredential("my username", "my password");
IWebProxy proxy = HttpWebRequest.DefaultWebProxy;
wb.Proxy = proxy;
wb.Credentials = creds;
wb.DownloadFile("source url", "C://downloaded.rpt.rsp");

but after processing destination file contains

Virtual user XXX logged in successfully

Answer 1

Your code seems correct. Did you try to manually download that file via a web-browser (like IE or chrome) and see what it downloads? If it still gets that, maybe the server is re-directing the URL to somewhere. plz check.

Just for your reference, the minimal code (without auth and proxy) to download a file.

using (WebClient Client = new WebClient ())
{
    Client.DownloadFile("http://www.abc.com/file/song/a.mpeg", "a.mpeg");
}

Answer 2

It seems like 2 step response from the server side. Authentication (with cookie) and redirect to the file.

You can see the details when downloading with the browser with a Fiddler on. The browser does a redirect and that won't work when doing Http request.

Try requesting with httpWebRequest and cookie container. And call it again with the authentication cookie.

Answer 3

I think you need to do two steps, 1) login, 2) download file.

Try this:

CookieAwareWebClient wb = new CookieAwareWebClient();
string response = wb.DownloadString("source url"); //should say Virtual user XXX Logged in
wb.DownloadFile("source url", "C://downloaded.rpt.rsp");

Be sure you are using CookieAwareWebClient:

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;
        }
    }