js模拟下载

            <a id="downFile" href="" style="display: none;"><span id="fp"></span></a>

$.post('../Handler/DownFileHandler.ashx', { action: "downfile", filename: res.FILE }, function (downRes) {
                                    $("#downFile").attr("href", "../Handler/DownFileHandler.ashx?url=" + downRes);
                                    $("#fp").click();
                                });