js实现单个的二维码生成和下载

/*用到的插件：qrcode.js*/

function makeQrcode(linkSite,linkName,i) {
var qrcode = new QRCode('qrcode', {
text: linkSite,
width: 128,
height: 128,
colorDark : '#000000',
colorLight : '#ffffff',
correctLevel : QRCode.CorrectLevel.H
});
/*var qrName = document.getElementById("qrname").innerText; //此处的获取没有实现*/

var canvas = document.getElementById("qrcode").getElementsByTagName("canvas");
/* var z = new ZipArchive();
z.addFileImage(linkName+".png",canvas[i].toDataURL());*/
var a = document.createElement('a');
/* a.download = 'xds' + new Date().getTime() || '下载图片名称';*/
a.download = linkName;
a.href = canvas[i].toDataURL();
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
}
/*ajax获取后台传来的json数据*/
function getAllChannel(id) {
$.ajax({
type: "GET",
url: "${ctx}/channel/channel/download",
data: {id: id},