public static async Task <HtmlDocument> OpenHtmlPageAsync(string url, PortableWebClient client)
{
var doc = new HtmlDocument();
LOAD_PAGE:
doc.LoadHtml(await client.DownloadStringAsync(url));
string title = GetTitle(doc);
// 处理重定向。
if (title.ToLowerInvariant().Contains("object moved"))
{
var nextUrl = doc.DocumentNode.Descendants("a").FirstOrDefault()?.GetAttributeValue("href", "");
if (!string.IsNullOrEmpty(nextUrl))
{
url = nextUrl;
goto LOAD_PAGE;
}
throw new UnexpectedHtmlException(url, "无法解析重定向目标。");
}
// 有时 CAS 中间会多一步。
if (title.Contains("统一身份认证网关"))
{
var loginForm = doc.GetElementById("fm1");
if (loginForm?.Name != "form")
{
loginForm = null;
}
if (loginForm == null)
{
/*
* <div id="content" class="fl-screenNavigator-scroll-container" >
* <div class="info"><p>单击 <a href="http://my.xjtu.edu.cn/Login?ticket=....">这里</a> ，便能够访问到目标应用。</p></div>
* </div>
*/
var node = doc.GetElementById("content");
var nextUrl = node?.Descendants("a").FirstOrDefault()?.GetAttributeValue("href", "");
if (!string.IsNullOrEmpty(nextUrl))
{
url = nextUrl;
goto LOAD_PAGE;
}
throw new UnexpectedHtmlException(url, "无法解析重定向目标。");
}
}
return(doc);
}
public static async Task<HtmlDocument> OpenHtmlPageAsync(string url, PortableWebClient client)
{
var doc = new HtmlDocument();
LOAD_PAGE:
doc.LoadHtml(await client.DownloadStringAsync(url));
string title = GetTitle(doc);
// 处理重定向。
if (title.ToLowerInvariant().Contains("object moved"))
{
var nextUrl = doc.DocumentNode.Descendants("a").FirstOrDefault()?.GetAttributeValue("href", "");
if (!string.IsNullOrEmpty(nextUrl))
{
url = nextUrl;
goto LOAD_PAGE;
}
throw new UnexpectedHtmlException(url, "无法解析重定向目标。");
}
// 有时 CAS 中间会多一步。
if (title.Contains("统一身份认证网关"))
{
var loginForm = doc.GetElementById("fm1");
if (loginForm?.Name != "form") loginForm = null;
if (loginForm == null)
{
/*
<div id="content" class="fl-screenNavigator-scroll-container" >
<div class="info"><p>单击 <a href="http://my.xjtu.edu.cn/Login?ticket=....">这里</a> ，便能够访问到目标应用。</p></div>
</div>
*/
var node = doc.GetElementById("content");
var nextUrl = node?.Descendants("a").FirstOrDefault()?.GetAttributeValue("href", "");
if (!string.IsNullOrEmpty(nextUrl))
{
url = nextUrl;
goto LOAD_PAGE;
}
throw new UnexpectedHtmlException(url, "无法解析重定向目标。");
}
}
return doc;
}
