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();