通过 C# 登录到网站，导航到另一个网页，然后将源代码输出为字符串

为了在登录后使用HttpWebRequest访问辅助URL，您需要记住一些事项。

首先，正如Casperah所提到的，您需要检查登录表单并确定用于接收登录数据的控件的"name"属性。

完成此操作后，您需要相应地格式化帖子字符串并将其提供给 WebRequest。

最后一个注意事项是，一旦您登录，您将需要存储和维护从保持您登录的服务器分配给您的cookie。

我从这篇 msdn 文章中获取了一个 WebRequest 代码段，并对其进行了修改以在登录后执行第二个页面请求。

        string loginurl = "http://www.gmail.com";
        string secondurl = "http://mail.google.com/prefs";
        string username = "bob@gmail.com";
        string password = "12345";
        GetSecondaryLoginPage(loginurl, secondurl, username, password);

    public string GetSecondaryLoginPage(string loginurl, string secondurl, string username, string password, string cookieName = null)
    {
        // Create a request using a URL that can receive a post. 
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(loginurl);
        // Set the Method property of the request to POST.
        request.Method = "POST";
        CookieContainer container = new CookieContainer();
        if (cookieName != null)
            container.Add(new Cookie(cookieName, username, "/", new Uri(loginurl).Host));
        request.CookieContainer = container;
        // Create POST data and convert it to a byte array.  Modify this line accordingly
        string postData = String.Format("username={0}&password={1}", username, password);
        ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(AcceptAllCertifications);
        byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        // Set the ContentType property of the WebRequest.
        request.ContentType = "application/x-www-form-urlencoded";
        // Set the ContentLength property of the WebRequest.
        request.ContentLength = byteArray.Length;
        // Get the request stream.
        Stream dataStream = request.GetRequestStream();
        // Write the data to the request stream.
        dataStream.Write(byteArray, 0, byteArray.Length);
        // Close the Stream object.
        dataStream.Close();
        // Get the response.
        WebResponse response = request.GetResponse();
        // Get the stream containing content returned by the server.
        dataStream = response.GetResponseStream();
        // Open the stream using a StreamReader for easy access.
        StreamReader reader = new StreamReader(dataStream);
        // Read the content.
        string responseFromServer = reader.ReadToEnd();
        using (StreamWriter outfile =
        new StreamWriter("output.html"))
        {
            outfile.Write(responseFromServer.ToString());
        }
        // Clean up the streams.
        reader.Close();
        dataStream.Close();
        response.Close();
        request = (HttpWebRequest)WebRequest.Create(secondurl);
        request.CookieContainer = container;
        response = request.GetResponse();
        // Get the stream containing content returned by the server.
        dataStream = response.GetResponseStream();
        // Open the stream using a StreamReader for easy access.
        reader = new StreamReader(dataStream);
        // Read the content.
        responseFromServer = reader.ReadToEnd();
        // Clean up the streams.
        reader.Close();
        dataStream.Close();
        response.Close();
        return responseFromServer;
    }

    public bool AcceptAllCertifications(object sender, System.Security.Cryptography.X509Certificates.X509Certificate certification, System.Security.Cryptography.X509Certificates.X509Chain chain, System.Net.Security.SslPolicyErrors sslPolicyErrors)
    {
        return true;
    }

唯一添加的行用于 postData 和 cookie。

您将需要修改该行

string postData = String.Format("username={0}&password={1}", username, password);

根据您在表单上的控件，由于您发布了您尝试使用的网站，我可以猜测您可能正在寻找

string postData = String.Format("uid={0}&portalBase=cwa&password={1}", username, password);

在表单中使用WebBrowser相当容易。 首先导航到 cwaLogon.jsp 页面，找到输入控件并调用"单击"提交按钮。要么这样做，要么使用HTTPWebRequest and Response进行适当的GET/POST。使用 Fiddler2 检查要发布的内容是一个很好的开始。