等待WebBrowser控件加载并运行所有JavaScript

Question

using (var browser = new WebBrowser()) {
    browser.Navigate(location);

    browser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(wb_DocumentCompleted);
    while (browser.ReadyState != WebBrowserReadyState.Complete) {
        Application.DoEvents();
    }
    log.Info("READY " + browser.Document.GetElementById("main").InnerText);
}

private void wb_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) {
    WebBrowser wb = (WebBrowser)sender;
    log.Info("COMPLETED " + wb.Document.GetElementById("main").InnerText);
}

两个日志都返回尚未应用JavaScript更改的元素.

现在我在WinForms中有另一个WebBrowser,它将在启动时加载页面.这次我也使用了这个DocumentCompleted活动,但是我没有得到任何javascripted消息.

form.webBrowser1.DocumentCompleted += (sender, e) => {
    log.Info("READY HIAAR" + form.webBrowser1.Document.GetElementById("main").InnerText);
};

最后,我尝试使用按钮获取源代码.首先我让WebBrowser在WinForms中加载页面,然后在5秒后按下按钮:

form.dataButton.Click += (sender, e) => {
    log.Info("READY HIAAR" + form.webBrowser1.Document.GetElementById("main").InnerText);
};

只有最后一个log.info返回我需要的实际内容.

如何在所有JavaScript加载并运行时捕获事件？点击击败目的.