Selenium webdriver window handles c# switchTo failed

Question

Here comes 2 windows pop out during the testing.

my code:

string BaseWindow = driver.CurrentWindowHandle;                 
ReadOnlyCollection

        

Answer 1

        IWebDriver popup = null;
        string mainWindow = driver.CurrentWindowHandle;
        bool foundPopupTitle = false;
        foreach (string handle in driver.WindowHandles)
        {
            popup = driver.SwitchTo().Window(handle);
            if (popup.Title.Contains(title))
            {
                foundPopupTitle = true;
                break;
            }
        }

        if (foundPopupTitle)
        {
            popup.Close();
        }
        //switch back to original window
        driver.SwitchTo().Window(mainWindow);