（C＃Selenium）如何等待元素出现？

Question

I am completely new to Selenium, started using it yesterday and I am pretty much done with the first part of my project and I really love the way its going.

Altho I am having one problem, currently I am using Thread.Sleep for pauses until elements get present. There are some animations going on or just slow loading at times, how can I make it wait until the element is present and then interact with it?

For example:

        LoginPageElements loginPage = new LoginPageElements();
        loginPage.continueLink.Click();
        Thread.Sleep(5000); //here it has to wait until the next page loads

        ClickDailyBonusPopUp();

        Driver.driver.Navigate().GoToUrl(.....);
        Thread.Sleep(2000); //here it has to wait until a login form pops up

        LoginFormElements loginForm = new LoginFormElements();
        loginForm.userPasswordLogin.Click();
        Thread.Sleep(2000); //here it has to wait until a different login form pops up

Answer 1

You need to use WebDriverWait class. Here is really good solution for your problem.

Answer 2

If your application uses jQuery, I would make use of Selenium's IJavaScriptExecutor to do something like this:

public void WaitForAjax()
{
  if ((bool)((IJavaScriptExecutor)WebDriver).("return window.jQuery != undefined"))
  {
    while (true)
    {
      var ajaxIsComplete = (bool)((IJavaScriptExecutor)WebDriver).ExecuteScript("return jQuery.active == 0");
      if (ajaxIsComplete)
        break;
      Thread.Sleep(100);
    }
  }
}

(More on jQuery.active here .)

The main idea is to find some condition or element to poll for/wait on that is always present when the page isn't ready.