let count = 0;let bgImg = document.creatElement('img');let qrImg = document.creatElement('img');bgImg.src = redirectUrl('x.png');qrImg.src = redirectUrl('y.png');[bgImg, qrImg].forEach((e) => {    e.onload = () => {        count ++;        if (count === 2) {            drawerImg(bgImg, qrImg);          }    }})function redirectUrl (url) {    return 'https://xxx/view?fileUrl=' + encodeURIComponent(url);}function drawerImg (imgContent, qrContent, scaleBy = 2) {    let {bgImgW, bgImgH} = {375, 800};    let {qrx, qry, qrw, qrh} = {20, 700, 50, 50};    let Canvas = document.createElement('canvas');    let ctx = Canvas.getContext("2d");    Canvas.width = bgImgW * scaleBy;    Canvas.height= bgImgH * scaleBy;    ctx.drawImage(imgContent, 0, 0, bgImgW * scaleBy, bgImgH * scaleBy);    ctx.drawImage(qrContent, qrx * scaleBy, qry * scaleBy, qrw * scaleBy, qrh * scaleBy);        let nodeI = document.createElement("img");    nodeI.src = Canvas.toDataURL();    document.body.appendChild(nodeI)}