支持的浏览器
Firefox 3.5+
Google Chrome
Opera 12+
IE11+
Safari 6+
基本语法
//两个参数:所需要截图的元素id,截图后要执行的函数, canvas为截图后返回的最后一个canvas html2canvas(document.getElementById('id')).then(function(canvas) {document.body.appendChild(canvas);});可用参数
参数名称 | 类型 | 默认值 | 描述 |
---|---|---|---|
allowTaint | boolean | false | Whether to allow cross-origin images to taint the canvas---允许跨域 |
background | string | #fff | Canvas background color, if none is specified in DOM. Set undefined for transparent---canvas的背景颜色,如果没有设定默认透明 |
height | number | null | Define the heigt of the canvas in pixels. If null, renders with full height of the window.---canvas高度设定 |
letterRendering | boolean | false | Whether to render each letter seperately. Necessary if letter-spacing is used.---在设置了字间距的时候有用 |
logging | boolean | false | Whether to log events in the console.---在console.log()中输出信息 |
proxy | string | undefined | Url to the proxy which is to be used for loading cross-origin images. If left empty, cross-origin images won't be loaded.---代理地址 |
taintTest | boolean | true | Whether to test each image if it taints the canvas before drawing them---是否在渲染前测试图片 |
timeout | number | 0 | Timeout for loading images, in milliseconds. Setting it to 0 will result in no timeout.---图片加载延迟,默认延迟为0,单位毫秒 |
width | number | null | Define the width of the canvas in pixels. If null, renders with full width of the window.---canvas宽度 |
useCORS | boolean | false | Whether to attempt to load cross-origin images as CORS served, before reverting back to proxy--这个我也不知道是干嘛的 |
例子
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>html2canvas example</title> <script type="text/javascript" src="html2canvas.js"></script> </head> <script type="text/javascript"> function takeScreenshot() { console.log('test'); html2canvas(document.getElementById('view'), { onrendered: function(canvas) { document.body.appendChild(canvas); }, // width: 300, // height: 300 }); } </script> <body> <div id="view" style="background:url(test.jpg) 50%; width: 700px; height: 500px;"> <input type="button" value="截图" onclick="takeScreenshot()"> </div> </body> </html>下面是我爱模板网利用 html2canvas 生成的图片:
遇到的问题
1、由于 html2canvas.js 不支持css3的高斯模糊滤镜,所以,我是先用js将图片生成高斯模糊的canvas定位到了底层,再使用html2canvas.js生成整个页面,参见:canvas实现高斯模糊
2、html2canvas.js使用了Promise,IE11-浏览器不支持,要做下兼容处理:
if (!window.Promise) {document.write('<script src="//www.5imoban.net/download/js/promise/es6-promise.min.js"><\/script><script>ES6Promise.polyfill()<\/script>');')