js实现图片下载

<img  src='src' data-name='自定义名称'>
<script>
//js实现图片下载
function download(){
        var name = $('#downImg').attr("data-name");
        var url = $('#downImg').attr("src");
        var a = document.createElement('a')
        var event = new MouseEvent('click')
        a.download = name || '下载图片名称'
        a.href = url
        a.dispatchEvent(event)
}
</script>