Webdriver是否找不到SharePoint对话框？

Question

在这里，我正在切换到相框。但它没有切换其iframe

List<WebElement> we = Testfactory.driver.findElements(By.xpath("//iframe[@class]"));

         int iSize = we.size();

            for (int i = 0; i < iSize; i++) {

                we.get(0).click();

                Testfactory.driver.switchTo().frame(0);


            }
        boolean b;
        b = Testfactory.driver.findElement(By.xpath("//select[@title='2013 MRA Choice']")).isEnabled();
        Assert.assertFalse(b);
        System.out.println("passs" +b);