DotNetBrowser API provides functionality that you can use to handle loading and decide whether specified URL should be loaded in Chromium engine or not. The following sample code demonstrates how to register LoadHandler which will cancel navigation to all URLs that start with http://www.google: 



private class CustomLoadHandler : DefaultLoadHandler
{
  public override bool OnLoad(LoadParams loadParams)
  {
    return loadParams.Url.StartsWith(@"http://www.google");
  }
}


browser.LoadHandler = new CustomLoadHandler();