Processing download files under ajax post submission

/*
     *下载文件
     * options:{
     *      url:'',  //下载地址
     *      isNewWinOpen:false,是否新窗口打开
     *      data:{name:value}, //要发送的数据
     *      method:'post'
     * }
     */
    function downLoadFile(url, data, method, isNewWinOpen) {
        var config = {
            url: url,
            data: (data = data || {}),
            method: (method = method || "GET"),
            isNewWinOpen: (isNewWinOpen = isNewWinOpen || false)
        };
        var $iframe = $('<div style="display: none"><iframe id="down-file-iframe" name="down-file-iframe" /></div>');
        var $form = $('<form target="down-file-iframe" method="' + config.method + '" action="' + config.url + '" />');
        if (config.isNewWinOpen) {
            $form.attr("target", "_blank");
        }
        /*拼接参数*/
        for (var key in config.data) {
            $form.append('<input type="hidden" name="' + key + '" value="' + config.data[key] + '" />');
        }
        $iframe.append($form);
        $(document.body).append($iframe);
        $form.submit();
        setTimeout(function () {
            $iframe.remove();
        }, 1000)
    }