扩展新函数给window

page.exposeFunction(name, puppeteerFunction)

• name <string> Name of the function on the window object
• puppeteerFunction <function> Callback function which will be called in Puppeteer's context.
• returns: <Promise>

The method adds a function called name on the page's window object. When called, the function executes puppeteerFunction in node.js and returns a Promise which resolves to the return value of puppeteerFunction.

If the puppeteerFunction returns a Promise, it will be awaited.

NOTE Functions installed via page.exposeFunction survive navigations.

An example of adding an md5 function into the page:

const puppeteer = require('puppeteer'); const crypto = require('crypto'); puppeteer.launch().then(async browser => { const page = await browser.newPage(); page.on('console', msg => console.log(msg.text())); await page.exposeFunction('md5', text => crypto.createHash('md5').update(text).digest('hex') ); await page.evaluate(async () => { // use window.md5 to compute hashes const myString = 'PUPPETEER'; const myHash = await window.md5(myString); console.log(`md5 of ${myString} is ${myHash}`); }); await browser.close(); });

An example of adding a window.readfile function into the page:

const puppeteer = require('puppeteer'); const fs = require('fs'); puppeteer.launch().then(async browser => { const page = await browser.newPage(); page.on('console', msg => console.log(msg.text())); await page.exposeFunction('readfile', async filePath => { return new Promise((resolve, reject) => { fs.readFile(filePath, 'utf8', (err, text) => { if (err) reject(err); else resolve(text); }); }); }); await page.evaluate(async () => { // use window.readfile to read contents of a file const content = await window.readfile('/etc/hosts'); console.log(content); }); await browser.close(); });