简介
html2canvas 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。这个html2canvas脚本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。
html2canvas可以通过获取HTML的某个元素,然后生成Canvas,能让用户保存为图片。 这个项目主要是生成canvas,那么我们如果需要生成图片还需要将它转化为图片地址。
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)
})
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--是否尝试使用CORS从服务器加载图像 |
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>
标签:.---,插件,Whether,canvas,html2canvas,images,document,小结
From: https://www.cnblogs.com/yyshow/p/17326615.html