Analysis of the method of generating QR code images from links using JS

<p id="code"></p>
<img id="img"/>
<script type="text/javascript">
  var qrcode=$("#code").qrcode({
    render:'canvas||table',
    width: 200, //宽度
    height:200, //高度
    text: "http://www.baidu.com" //任意内容
  }).hide();
  var canvas=qrcode.find('canvas').get(0);
  //如果有循环,此句必不可少 qrcode.find('canvas').remove();
  var data = canvas.toDataURL('image/jpg');
  $('#img').attr('src',data) ;
  saveFile(data,"fd范德萨范德萨");
  //转为图片的方法,需要上门的data
  function saveFile(data,filename){
    var save_link=document.createElementNS('http://www.w3.org/1999/xhtml', 'a');
    save_link.href=data;
    save_link.download=filename;
    var event=document.createEvent('MouseEvents');
    event.initMouseEvent('click',true,false,window,0,0,0,0,0,false,false,false,false,0,null);
    save_link.dispatchEvent(event);
  };
</script>