无法在Selenium中的模式弹出窗口上找到元素

该网站非常慢，并且存在加载问题。因此，我建议您对每个findElement使用Explicit等待。我写了以下脚本，效果很好

WebDriver driver = new ChromeDriver();
driver.manage().window().maximize();        

driver.get("http://www.walmart.com/");
WebDriverWait wait = new WebDriverWait(driver, 20);
wait.until(ExpectedConditions.elementToBeClickable(By.cssSelector("[placeholder='Search']")))
        .sendKeys("TV");
driver.findElement(By.cssSelector(".searchbar-submit.js-searchbar-submit")).click();
wait.until(ExpectedConditions.presenceOfAllElementsLocatedBy(By.cssSelector("#tile-container>div>a>img")))
        .get(0).click();        
wait.until(ExpectedConditions.elementToBeClickable(By.id("WMItemAddToCartBtn"))).click();
wait.until(ExpectedConditions.elementToBeClickable(By.id("PACCheckoutBtn"))).click();