标签download无法下载在线图片解决

let imgUrl = 'http://118.178.44.182:9080/hzzutil/mdfiles/' + e + '.jpg';

fetch(imgUrl).then(res => res.blob()).then(blob => {   // 将链接地址字符内容转变成blob地址
    document.getElementById('downBtn')['href'] = URL.createObjectURL(blob);
});

<a id="downBtn" href="" download>下载</a>