分度器与Typescript。失败。不能读取未定义的属性'presenceOf'。

Question

我想用protractor、typecript来等待元素的存在。

以下是我的代码。

import { browser, by, element } from 'protractor';
import { protractor } from 'protractor/built/ptor';

export class LoginPage {

    title = element(by.css('my-page > h3'));

    async openMyPage() {
        await browser.get(browser.baseUrl);
        await browser.wait(protractor.ExpectedConditions.presenceOf(this.title), 5000,
            "Title does not appear during 5 seconds")
    }
}

它以错误的方式失败了: Failed: Cannot read property 'presenceOf' of undefined.

谁能帮我理解这个原因？以及如何解决？

Answer 1

试试这样。

import { browser, by, element, ElementFinder, protractor } from 'protractor';

export class NameofClass {

public title: ElementFinder;

constructor() {

this.title = element(by.css('my-page > h3'));
}

async openMyPage() {
        await browser.get(browser.baseUrl);
        await browser.wait(protractor.ExpectedConditions.presenceOf(this.title), 5000,
            "Title does not appear during 5 seconds")
    }
}