如何让Selenium 2.0等待页面加载?


当前回答

如果你想等待一个特定的元素加载,你可以在RenderedWebElement上使用isdisplay()方法:

// Sleep until the div we want is visible or 5 seconds is over
long end = System.currentTimeMillis() + 5000;
while (System.currentTimeMillis() < end) {
    // Browsers which render content (such as Firefox and IE) return "RenderedWebElements"
    RenderedWebElement resultsDiv = (RenderedWebElement) driver.findElement(By.className("gac_m"));

    // If results have been returned, the results are displayed in a drop down.
    if (resultsDiv.isDisplayed()) {
      break;
    }
}

(例子来自《5分钟入门指南》)

其他回答

使用类WebDriverWait

也可以看这里

您可以期望显示一些元素。类似于c#:

WebDriver _driver = new WebDriver();
WebDriverWait _wait = new WebDriverWait(_driver, new TimeSpan(0, 1, 0));

_wait.Until(d => d.FindElement(By.Id("Id_Your_UIElement")));

你可以显式地等待一个元素出现在网页上,然后才可以采取任何操作(如element.click()):

driver.get("http://somedomain/url_that_delays_loading");
WebElement myDynamicElement = (new WebDriverWait(driver, 10))
    .until(new ExpectedCondition<WebElement>() {
        @Override
        public WebElement apply(WebDriver d) {
            return d.findElement(By.id("myDynamicElement"));
        }
    }
);

这是我用于类似场景的方法,效果很好。

对于隐式等待,你可以使用如下代码:

driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS)

为了使网页等待一个特定的对象是可见的或某些条件是真实的。您可以使用网页驱动程序等羽。

//120 is maximum number of seconds to wait.
WebDriverWait wait = new WebDriverWait(driver,120);  
wait.until(ExpectedConditions.elementToBeClickable("CONDITITON"));

在Java中,另一种选择是让线程在特定的时间内休眠。

Thread.sleep(numberOfSeconds*1000); 
//This line will cause thread to sleep for seconds as variable

我创建了一个方法来简化线程。睡眠的方法

public static void wait_time(int seconds){
    try {
        Thread.sleep(seconds*1000);
        }catch (InterruptedException e) {
        // TODO Auto-generated catch block
            e.printStackTrace();
        }
}

使用wait_time(10)方法;线程将休眠10秒。

private static void checkPageIsReady(WebDriver driver) {
    JavascriptExecutor js = (JavascriptExecutor) driver;

    // Initially bellow given if condition will check ready state of page.
    if (js.executeScript("return document.readyState").toString().equals("complete")) {
        System.out.println("Page Is loaded.");
        return;
    }

    // This loop will rotate for 25 times to check If page Is ready after
    // every 1 second.
    // You can replace your value with 25 If you wants to Increase or
    // decrease wait time.
    for (int i = 0; i < 25; i++) {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
        }
        // To check page ready state.
        if (js.executeScript("return document.readyState").toString().equals("complete")) {
            break;
        }
    }
}

伙计,所有这些答案都需要太多代码。这应该是一个简单的事情,因为它很常见。

为什么不注入一些简单的Javascript与web驱动程序和检查。 这就是我在webscraper课上使用的方法。Javascript是相当基本的,即使你不知道它。

def js_get_page_state(self):
"""
Javascript for getting document.readyState
:return: Pages state. See doc link below.
"""
ready_state = self.driver.execute_script('return document.readyState')
if ready_state == 'loading':
    self.logger.info("Loading Page...")
elif ready_state == 'interactive':
    self.logger.info("Page is interactive")
elif ready_state == 'complete':
    self.logger.info("The page is fully loaded!")
return ready_state

更多信息见“文档”。MDN Web Docs的readyState: https://developer.mozilla.org/en-US/docs/Web/API/Document/readyState