如何在Puppeteer和NodeJS中把提示框的消息分配给一个变量？

Posted 2021-03-19

let a = "";
(async () => {
 const browser = await puppeteer.launch()
 const page = await browser.newPage()
 await page.goto('https://www.google.com/')
 page.on('dialog', async dialog => {
 **a = dialog.message();**
  await dialog.dismiss()
 })
 await page.evaluate(() => alert('This message is inside an alert box'))
 **console.log(a);**
 await browser.close()
})()

我想把对话框的消息分配给一个变量，并在page.on函数之外访问它。

答案

你可以使用一个承诺，它将在事件中被解析，然后等待这个承诺。

const browser = await puppeteer.launch({
    headless: false,
    defaultViewport: null
});
let resolve;
var dialogPromise = new Promise(x => resolve = x);
const Page = await browser.newPage();
await Page.goto('https://www.google.com/');
page.on('dialog', async dialog => {
  resolve(dialog.message());
  await dialog.dismiss()
 })
var output = await dialogPromise;
console.log(output);