在C#WinForms示例应用程序中,我使用了WebBrowser控件。我想使用JavaScript XPath来选择单个节点。为此,我使用XPathJS
但是使用以下代码, vResult 的返回值始终为NULL。
bool completed = false;
WebBrowser wb = new WebBrowser();
wb.ScriptErrorsSuppressed = true;
wb.DocumentCompleted += delegate { completed = true; };
wb.Navigate("http://stackoverflow.com/");
while (!completed)
{
Application.DoEvents();
Thread.Sleep(100);
}
if (wb.Document != null)
{
HtmlElement head = wb.Document.GetElementsByTagName("head")[0];
HtmlElement scriptEl = wb.Document.CreateElement("script");
mshtml.IHTMLScriptElement element = (mshtml.IHTMLScriptElement)scriptEl.DomElement;
element.src = "https://raw.github.com/andrejpavlovic/xpathjs/master/build/xpathjs.min.js";
head.AppendChild(scriptEl);
// Initialize XPathJS
wb.Document.InvokeScript("XPathJS.bindDomLevel3XPath");
string xPathQuery = @"count(//script)";
string code = string.Format("document.evaluate('{0}', document, null, XPathResult.ANY_TYPE, null);", xPathQuery);
var vResult = wb.Document.InvokeScript("eval", new object[] { code });
}
有没有办法使用WebBrowser控件执行JavaScript XPath?
Rem :我想避免使用HTML Agility Pack,我想直接操作WebBrowser控件的DOM内容mshtml.IHTMLElement
答案 0 :(得分:1)
我找到了解决方案,这里是代码:
bool completed = false;
WebBrowser wb = new WebBrowser();
wb.ScriptErrorsSuppressed = true;
wb.DocumentCompleted += delegate { completed = true; };
wb.Navigate("http://stackoverflow.com/");
while (!completed)
{
Application.DoEvents();
Thread.Sleep(100);
}
if (wb.Document != null)
{
HtmlElement head = wb.Document.GetElementsByTagName("head")[0];
HtmlElement scriptEl = wb.Document.CreateElement("script");
mshtml.IHTMLScriptElement element = (mshtml.IHTMLScriptElement)scriptEl.DomElement;
element.text = System.IO.File.ReadAllText(@"wgxpath.install.js");
head.AppendChild(scriptEl);
// Call wgxpath.install() from JavaScript code, which will ensure document.evaluate
wb.Document.InvokeScript("eval", new object[] { "wgxpath.install()" });
string xPathQuery = @"count(//script)";
string code = string.Format("document.evaluate('{0}', document, null, XPathResult.NUMBER_TYPE, null).numberValue;", xPathQuery);
int iResult = (int) wb.Document.InvokeScript("eval", new object[] { code });
}
我使用" 一个纯JavaScript XPath库":wicked-good-xpath并下载wgxpath.install.js
答案 1 :(得分:-2)
Javascript无法在WebBrowser上运行。如果你想要Javascript功能,请使用PhantomJS / Selenium。