利用html2canvas.js将网页中dom元素转换成图片，html2canvas.js的链接是：http://html2canvas.hertzen.com/
实现效果demo的代码如下：
<!DOCTYPE html><html lang="en"><head> ???<meta charset="UTF-8"> ???<title>网页转图片</title> ???<style> ???#img { ???????position: fixed; ???????top: 0px; ???????left: 0px; ???????opacity: 1; ???????transform: scale(0.8); ???????z-index: 99999999; ???????transition: transform 0.3s cubic-bezier(0.42, 0, 0.58, 1), opacity 0.3s cubic-bezier(0.42, 0, 0.58, 1), -webkit-transform 0.3s cubic-bezier(0.42, 0, 0.58, 1) ???} ???</style> ???<script type="text/javascript" src="http://html2canvas.hertzen.com/dist/html2canvas.min.js"></script> ???<script src="http://code.jquery.com/jquery-1.8.3.min.js"></script></head><body> ???<div id="capture" style="padding: 10px; background: #f5da55"> ???????<h4 style="color: #000; ">Hello world!</h4> ???</div> ???<button id="btn">点击</button> ???<img id="img" /> ???<script type="text/javascript"> ???var element = document.querySelector(‘body‘); ???var image = document.querySelector(‘#img‘); ???$(‘#btn‘).on(‘click‘, function() { ???????html2image(element, image); ???}) ???function html2image(source, image) { ???????html2canvas(source).then(canvas => { ???????????var imageData = canvas.toDataURL("image/png"); ???????????image.src = imageData; ???????????// document.body.appendChild(canvas); ???????????sessionStorage.setItem(‘imageSrc‘, imageData); ???????}); ???} ???$.fn.longPress = function(fn) { //移动端长按屏幕方法 ???????var timeout = undefined; ???????var $this = this; ???????for (var i = 0; i < $this.length; i++) { ???????????$this[i].addEventListener(‘touchstart‘, function(event) { ???????????????timeout = setTimeout(fn, 2000); //长按时间超过2000ms，则执行传入的方法 ???????????}, false); ???????????$this[i].addEventListener(‘touchend‘, function(event) { ???????????????clearTimeout(timeout); //长按时间少于2000ms，不会执行传入的方法 ???????????}, false); ???????} ???} ???$(‘body‘).longPress(function() { ???????html2image(element, image); ???}); ???</script></body></html>
网页中DOM元素转换成图片
原文地址：https://www.cnblogs.com/leonmangochen/p/9420622.html