html2canvas属性和使用方法以及如何使用html2canvas将HTML内容写入Canvas生成图片
如何使用JS截取HTML页面为图片呢,下面为大家介绍一款JS截图插件html2canvas.js
html2canvas.js 能够实现在用户浏览器端直接对整个或部分页面进行截屏。
html2canvas.js可以将当页面渲染成一个Canvas图片,通过读取DOM并将不同的样式应用到这些元素上实现。
它不需要来自服务器任何渲染,整张图片都是在客户端浏览器创建。当
浏览器不支持Canvas时,将采用Flashcanvas或ExplorerCanvas技术代替实现。
以下浏览器能够很好的支持该脚本:Firefox 3.5+, Google Chrome, Opera新的版本, IE9以上的浏览器。
基本语法
html2canvas(element, options); html2canvas(document.body, { onrendered: function(canvas) { var url = canvas.toDataURL();//图片地址 document.body.appendChild(canvas); }, width: 300, height: 300
或者使用ES6的promise
//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);});
html2canvas基本参数说明
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>
效果图如下:
截图效果如下:
最后附上html2canvas官网链接
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