JavaScript如何实现文件的下载功能

function downFile(content, filename) {    // 创建隐藏的可下载链接
    var eleLink = document.createElement('a');
    eleLink.download = filename;
    eleLink.style.display = 'none';    // 字符内容转变成blob地址
    var blob = new Blob([content]);
    eleLink.href = URL.createObjectURL(blob);    // 触发点击    document.body.appendChild(eleLink);
    eleLink.click();    // 然后移除    document.body.removeChild(eleLink);
};

// if (typeof(download.iframe) == 'undefined') {
            //     var iframe = document.createElement('iframe');
            //     download.iframe = iframe;
            //     document.body.appendChild(download.iframe);
            // };
            // download.iframe.src = newdownloadUrl;
            // download.iframe.style.display = "none";

// var $eleForm = $("<form method='get'></form>");
            // $eleForm.attr("action", "https://codeload.github.com/douban/douban-client/legacy.zip/master");
            // $eleForm.attr("action", url);
            // $(document.body).append($eleForm);
            // $eleForm.submit();