Get Window Handles

The Get Window Handles command of the WebDriver API returns a list of all WebWindows. Each tab or window, depending on whether you are using a tabbed browser, is associated by a window handle that is used as a reference when switching to the window.

In order to determine whether or not a particular interaction with the browser opens a new window, one can obtain the set of window handles before the interaction is performed and compare it with the set after the action is performed.

using System.Collections.ObjectModel;
using OpenQA.Selenium.Firefox;

namespace MDNWebDriverExamples
{
    class Example
    {
        public static void Main(string[] args)
        {
            FirefoxDriver session = new FirefoxDriver();

            session.ExecuteScript("window.open()");

            ReadOnlyCollection<string> currentWindowHandles = session.WindowHandles;
        }
    }
}