下載圖片到瀏覽器

function downloadIamge(selector, name) {
    // 通過選擇器獲取img元素，
    var img = document.querySelector(selector)
    // 將圖片的src屬性作爲URL地址
    var url = img.src
    var a = document.createElement('a')
    var event = new MouseEvent('click')
    a.download = name || '下載圖片名稱'
    a.href = url
    a.dispatchEvent(event)
}

<a style="color:blue;" οnclick="downloadIamge('.img1', '信息錄入二維碼.jpg')">下載二維碼</a>

//頁面實現簡單的下載功能
function OpenQzqdUrl(obj) {
    var file = obj.getAttribute("file");
    var sxUrl = "";
    if (file!=null) {
    var url = sxUrl + file;
        window.open(url);
    }
}

<a href='javascript:void(0);' file='"+mapa.get("file_url")+"' οnclick='OpenQzqdUrl(this)'>"+mapa.get("name")+"</a>