How to wait for a frame to load before locating an element?

问题

I'm trying to wait for Selenium to switch changing frames before waiting on another element. I.e.

var wait = new WebDriverWait(driver, 15);
wait.Until(ExpectedConditions.FrameToBeAvailableAndSwitchToIt(By.Id("frameA"));

var wait2 = new WebDriverWait(driver, 15);
// wait for element within frameA to exist
wait2.Until(ExpectedConditions.ElementExists(By.Id("elementA")));

If I toss in a simple Thread.Sleep(1000); before the second wait it functions fine, but without that I get the following error:

'unknown error: unhandled inspector error: {"code":-32000,"message":"Cannot find context with specified id"}
    enter code here

Is there a better way to wait for the frame context to switch finishing before waiting for an element within that frame to be populated?

回答1:

There are a couple of things you need to consider :

The line of code to switch to the frame looks perfect which doesn't throws any error :

var wait = new WebDriverWait(driver, 15);
wait.Until(ExpectedConditions.FrameToBeAvailableAndSwitchToIt(By.Id("frameA"));

In the next line you have tried the ExpectedConditions method ElementExists. As per the API Docs ElementExists Method is defined as :

An expectation for checking that an element is present on the DOM of a page. This does not necessarily mean that the element is visible.

Selenium can't interact with elements until the element is visible. Hence you need to use the method ElementIsVisible as follows :

var wait2 = new WebDriverWait(driver, 15);
wait2.Until(ExpectedConditions.ElementIsVisible(By.Id("elementA")));

Here you can find a detailed discussion on Ways to deal with #document under iframe

回答2:

You can wait for the frame itself to be clickable:

wait2.Until(ExpectedConditions.ElementExists(By.Id("YOURFRAMEID")));

回答3:

This is how you can do it:

var wait = new WebDriverWait(new SystemClock(), driver, TimeSpan.FromSeconds(timeout), TimeSpan.FromSeconds(sleepInterval)); 
wait.Until(ExpectedConditions.FrameToBeAvailableAndSwitchToIt("yourFrameName"); 
driver.SwitchTo().Frame("yourFrameName");

回答4:

I am not sure which language you're working on. But in C#, you would need to SwitchTo default content first and then switch to the Iframe you're dealing with which is frameA. So here is my suggested code to try:

driver.SwitchTo().DefaultContent();
driver.SwitchTo().Frame(frameA);

Update: Implement a method that waits for element explicitly:

public void WaitForElementExplicitly(int WaitInMilliSeconds = 3000, By Selector = null)
{
  WebDriverWait wait = new WebDriverWait(CommonTestObjects.IWebDriver, TimeSpan.FromSeconds(WaitInMilliSeconds / 1000));
  IWebElement myDynamicElement = wait.Until<IWebElement>((d) =>
  {
    return d.FindElement(Selector);
  });
}

And then call the method to wait for your element

WaitForElementExplicitly(Selector: By.Id("elementA"));

来源：https://stackoverflow.com/questions/49677267/how-to-wait-for-a-frame-to-load-before-locating-an-element

标签

selenium

selenium-webdriver

webdriver

frames