html2canvas截图

npm install --save html2canvas
//要`element`使用带有一些（可选）[选项的](http://html2canvas.hertzen.com/configuration/)html2canvas呈现，只需调`html2canvas(element, options);`
/*html2canvas(document.body).then(function(canvas) {
    document.body.appendChild(canvas);
});*/

<div id="capture" >
    <div>
        <h3>Test</h3>
        <img src="" />
    </div>
</div>
<script>
      html2canvas(document.querySelector('#capture')).then(canvas=>{
            document.body.appendChild(canvas)
})
</script>