打开登录页面，插入登录信息，点击登录按钮

Question

我想打开一个登录页面，如www.site.com/login.php

插入用户名和密码

并调用登录按钮。

所有这些都应该在服务器中编程完成(而不是在浏览器中)。

有可能做到这一点吗？

Answer 1

如果希望以登录用户的身份触发请求，则必须在登录POST请求(可能设置登录cookie)和其他请求之间保留一个CookieContainer实例。

        var cookieJar = new CookieContainer();            
        var loginData = new Dictionary<string,string>() {
            // be carefull to use the same keys/names as the login form
            { "username", "LightWing" },
            { "password", "l33tPwD" } 
        };
        var request = (HttpWebRequest)WebRequest.Create("http://.../login.php");
        request.CookieContainer = cookieJar;
        request.AllowAutoRedirect = true;
        request.Method = "POST";

        // build the POST data
        byte[] dataBuffer = Encoding.ASCII.GetBytes(string.Join("&", loginData.AllKeys.Select(x => string.Concat(HttpUtility.UrlEncode(x), "=", HttpUtility.UrlEncode(loginData[x])))));
        request.ContentLength = dataBuffer.LongLength;
        request.ContentType = "application/x-www-form-urlencoded";
        using (var requestStream = request.GetRequestStream())
        {
            requestStream.Write(dataBuffer, 0, dataBuffer.Length);
            requestStream.Flush();
        }
        var response = request.GetResponse();
        using (var responseStream = response.GetResponseStream())
        {
            // do some reading if you want..
        }

        // now _cookieJar should contain the login cookie...
        // you can trigger further requests as a logged in user:
        request = (HttpWebRequest)WebRequest.Create("http://.../restrictedPage.php");
        request.CookieContainer = cookieJar; // reuse them cookies!
        request.AllowAutoRedirect = true;
        request.Method = "GET";
        var response = request.GetResponse();
        using (var responseStream = response.GetResponseStream())
        {
            // read the restricted page response
        }

我还编写了一个简单的实用程序来帮助您抓取使用回发的Asp.net WebForms页。你可以在here上找到它。

Answer 2

您可以对登录按钮提交的任何位置执行POST请求。只需在请求中传递用户名和密码即可。

Answer 3

每个登录页面通常采用以下格式：

<form action="login.extention" method="post or get">
<input name="username" type="text" />
<input name="password" type="password" />
</form>

您必须通过get或post将信息发送到操作页面。(通常是post)