从受保护的服务器asp.net下载文件 [英] asp.net Download files from protected server

问题描述

我寻觅各种论坛和链接，但没有带什么东西有用呢。

I have searched various forums and links but havn't got anything helpful yet.

其实我正努力使用C＃，允许使用登录远程服务器上，然后从服务器下载文件制定在ASP.net的Web应用程序。

Actually i working towards developing a web application in ASP.net using C# that enables use to login on a remote server and then download files from that server.

有curently读音字能够登录到该服务器，并看到受保护的页面的内容。

Curently i m able to login to that server and see the content of the protected page.

但是，当涉及到下载的文件，我得到一个取消授权访问错误。

But when it comes to download the file, i get an Unauthorize access error.

我为能够从服务器上下载图像，但这些都没有得到保护。

I m able to download images from the server but those are not protected.

在code到目前为止，我已经开发为

the code i have developed so far is

    protected void Unnamed1_Click(object sender, EventArgs e)
{
    try
    {

        string LOGIN_URL = "https://some.server/";

        // first, request the login form to get the value

        HttpWebRequest webRequest = WebRequest.Create(LOGIN_URL) as HttpWebRequest;
        webRequest.ContentType = "application/x-www-form-urlencoded";
        webRequest.KeepAlive = true;
        webRequest.UserAgent = userAgent;
        String received = Encoding.ASCII.GetString(Request.BinaryRead(Request.ContentLength));
        webRequest.ContentLength = received.Length;
        webRequest.Proxy.Credentials = new NetworkCredential("usrname", "password", "domain");
        StreamReader responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream(), Encoding.ASCII);
        string responseData = responseReader.ReadToEnd();
        responseReader.Close();
        string postData = "user=usr&password=pass&switch=Login";
        Response.Write(webRequest.Address);

        // have a cookie container ready to receive the forms auth cookie

        CookieContainer cookies = new CookieContainer();

        // now post to the login form

        webRequest = WebRequest.Create(LOGIN_URL) as HttpWebRequest;
        webRequest.Method = "POST";
        webRequest.ContentType = "application/x-www-form-urlencoded";
        webRequest.CookieContainer = cookies;

        // write the form values into the request message

        StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream());
        requestWriter.Write(postData);
        requestWriter.Close();

        // we don't need the contents of the response, just the cookie it issues 

        webRequest.GetResponse().Close();



        // Download files

        WebProxy myProxy = new WebProxy("server.https.com", 443);
        //WebRequest request = WebRequest.Create("https://some.server/file.zip");
        WebRequest request = WebRequest.Create("https://some.server/file.zip");
        request.Proxy.Credentials = new NetworkCredential("usrname", "password", "domain");

        string filename = "file.zip";
        string filepath = "C:\\Documents and Settings\\user\\Desktop\\" + filename.ToString();

        WebClient client = new WebClient();
        client.Credentials = new NetworkCredential("usrname", "password", "domain");
        client.DownloadFile("https://some.server/file.zip", filepath);
    }
    catch (Exception exp)
    {
        Response.Write(exp.ToString());
    }
}

在/的WebSite1应用程序中

服务器错误。

远程服务器返回错误：（401）未经授权。
说明：执行当前Web请求的执行过程中发生未处理的异常。请查看有关错误的详细信息的堆栈跟踪以及它起源于code。

Server Error in '/WebSite1' Application.

The remote server returned an error: (401) Unauthorized. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

异常详细信息：System.Net.WebException：远程服务器返回错误：（401）未经授权

Exception Details: System.Net.WebException: The remote server returned an error: (401) Unauthorized.

源错误：

80号线：Web客户端的客户端=新的WebClient（）;

Line 80: WebClient client = new WebClient();

81号线：client.Credentials =新的NetworkCredential（用户名，密码，域）;

Line 81: client.Credentials = new NetworkCredential("username", "password", "domain");

82号线：client.DownloadFile（HTTPS：//some.server/file.zip，文件路径）;

Line 82: client.DownloadFile("https://some.server/file.zip", filepath);

推荐答案

使用从WebClient的派生这个类。它总是会通过饼干的每个请求。

Use this class derived from WebClient. It will always pass the cookies with every request.

class WebClientWithCookies: WebClient
{
    private CookieContainer _container = new CookieContainer();

    protected override WebRequest GetWebRequest(Uri address) 
    {
        HttpWebRequest request = base.GetWebRequest(address) as HttpWebRequest; 

        if (request != null) 
        { 
            request.Method = "Post";
            request.CookieContainer = _container; 
        } 

        return request;
    }
}

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