使用nodejs去做一个验证码

let express = require(‘express‘);let captchapng = require(‘captchapng‘);let app = express();app.get(‘/cap‘,function (req, res) { ???res.render(‘html‘,{a,b,c,d}) ???????// width,height, ??numeric captcha ?数字验证码 ???//他这个图片 每个数字之间是 80 ?这个图片的高度是30 ???let num = parseInt(Math.random()*9000+1000); ???// cookie/session ???req.session.recode = num; ???let p = new captchapng(80,30,num); ???p.color(0, 0, 0, 0); ?// First color: background (red, green, blue, alpha) ???p.color(80, 80, 80, 255); // Second color: paint (red, green, blue, alpha) ???let img = p.getBase64(); ???//将 base64图片格式 转成了 buffer ???let imgbase64 = new Buffer(img,‘base64‘); ???res.set(‘Content-Type‘,‘image/png‘); ???res.send(imgbase64);});app.listen(3000,function () { ???console.log(‘start‘)});