javascript 量角器，使用 isDisplayed() 我得到 NoSuchElementError: No element found using locator
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Protractor, with isDisplayed() I get NoSuchElementError: No element found using locator
提问by Mikel
In protractor 2.0, I am checking in a expect()if one element is displayed. I expect a false, but the weird thing is that I get following error:
在量角器 2.0 中，我正在检查expect()是否显示一个元素。我期待一个错误，但奇怪的是我收到以下错误：
NoSuchElementError: No element found using locator: By.id("userForm")
NoSuchElementError：使用定位器找不到元素：By.id("userForm")
My code is:
我的代码是：
describe('closeModal', function() {
it('should close the alert that appears after registration.', function(){
element(by.id('closeAlertModalButton')).click();
expect(element(by.id('userForm')).isDisplayed()).toBeFalsy();
});
});
I understand that I get that error because element is not longer on the page (is what I want to confirm), but shouldn't I get a false and not a error?
我知道我收到该错误是因为页面上不再显示元素（这是我要确认的内容），但是我不应该得到错误而不是错误吗？
回答by alecxe
isDisplayed()would check if an element is visible or not, but you need to check whether an element is present in DOM or not, use isElementPresent()or isPresent():
isDisplayed()将检查元素是否可见，但您需要检查元素是否存在于 DOM 中，使用isElementPresent()or isPresent()：
expect(browser.isElementPresent(element(by.id('userForm')))).toBe(false);
expect(element(by.id('userForm')).isPresent()).toBe(false);
See also:
也可以看看：
回答by Vasiliy Vanchuk
This error is part of WebDriver behavior. For such cases you should better use isPresentor isElementPresent
此错误是 WebDriver 行为的一部分。对于这种情况，您最好使用 isPresent或isElementPresent
回答by Sergiy Podgorniy
If element visible do A if not visible do B, disregard exception if element not found:
如果元素可见做 A 如果不可见做 B，如果未找到元素则忽略异常：
element.isDisplayed().then(function(visible){
if (visible) {
// do A when element visible
}else{
// do B when element not visible
}
}, function () {
//suppress exception if element is not found on page
});
