MouseDown is disabled too. That's because mouse events are sent to the DOM. You can subscribe to DOM events with the HtmlElement.AttachEventHandler() method. For example:
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
webBrowser1.Url = new Uri("http://stackoverflow.com");
webBrowser1.DocumentCompleted += webBrowser1_DocumentCompleted;
}
void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) {
webBrowser1.Document.Body.AttachEventHandler("ondblclick", Document_DoubleClick);
}
void Document_DoubleClick(object sender, EventArgs e) {
MessageBox.Show("double click!");
}
}