在浏览器中批量下载文件(上)

一般来说浏览器要同时下载几个文件,比如pdf文件,会在服务器端把几个文件压缩成一个文件。但是导致的问题就是会消耗服务器的cpu和io资源。

   那有没有办法,用户点了几个文件,在客户端同时下载呢? 支持html5的浏览器是可以的,html的a标签有一个属性download

 <a download=”下载的1.pdf” href=”1.pdf”>单个文件下载</a>, 经过测试在edge浏览器,firefox和chrome都支持。但是遗憾的是ie浏览器不支持。参考下面的例子。

<!DOCTYPE html>

<html>

<head>

    <metacharset=“utf-8”>

    <metahttp-equiv=“X-UA-Compatible”content=“IE=Edge,chrome=1”>

    <title></title>

    <scriptsrc=“//libs.baidu.com/jquery/1.11.1/jquery.min.js”></script>

</head>

<body>

    <inputtype=“button”class=“downloadAll”value=批量下载”/>

    <script>

        var filesForDownload = [];

        filesForDownload[filesForDownload.length] = {

            path: “1.zip”//要下载的文件路径

            name: “file1.txt”//下载后要显示的名称

        };

        filesForDownload[filesForDownload.length] = {

            path: “2.zip”,

            name: “file2.txt”

        };

        filesForDownload[filesForDownload.length] = {

            path: “3.zip”,

            name: “file3.txt”

        };

 

        function download(obj) {

            var temporaryDownloadLink = document.createElement(“a”);

            temporaryDownloadLink.style.display = ‘none’;

            document.body.appendChild(temporaryDownloadLink);

            temporaryDownloadLink.setAttribute(‘href’, obj.path);

            temporaryDownloadLink.setAttribute(‘download’, obj.name);

            temporaryDownloadLink.click();

            document.body.removeChild(temporaryDownloadLink);

        }

 

        $(‘input.downloadAll’).click(function(e) {

            e.preventDefault();

            for (var x in filesForDownload) {

                download(filesForDownload[x]);

            }

        });

    </script>

</body>

</html>

ie浏览器怎么办呢? 也可以用window.open函数。

<!DOCTYPE html>

<html>

  <head>

    <metacharset=“utf-8”>

    <title></title>

    <scriptsrc=“//libs.baidu.com/jquery/1.11.1/jquery.min.js”></script>

  </head>

  <body>

    <adownload=下载的1.pdf”href=“1.pdf”>单个文件下载</a><br>

      <ahref=“#”class=“yourlink”>下载全部文件</a>

 

<script>

 

$(‘a.yourlink’).click(function(e) {

    e.preventDefault();

    window.open(‘1.zip’,‘download’);

    window.open(‘2.zip’,‘download’);

    window.open(‘3.zip’,‘download’);

});

</script>

  </body>

</html>

完整的方案就是根据浏览器类型,调用不同的函数,实现。

另外要下载pdf,而不是在浏览器中打开的话,需要配置apache的配置文件,在httpd.conf中增加下面的配置。

<FilesMatch “\.pdf$”>

   Header set Content-Disposition attachment

</FilesMatch>

 

或者使用down2组件,下载更简单。

JavaScript

引入头

<head>

    <metahttp-equiv=”Content-Type”content=”text/html; charset=utf-8″/>

    <title>donw2-多文件演示页面</title>

    <linktype=”text/css”href=”js/down.css”rel=”Stylesheet”/>

    <scripttype=”text/javascript”src=”js/jquery-1.4.min.js”></script>

    <scripttype=”text/javascript”src=”js/down.app.js”charset=”utf-8″></script>

    <scripttype=”text/javascript”src=”js/down.edge.js”charset=”utf-8″></script>

    <scripttype=”text/javascript”src=”js/down.file.js”charset=”utf-8″></script>

    <scripttype=”text/javascript”src=”js/down.folder.js”charset=”utf-8″></script>

    <scripttype=”text/javascript”src=”js/down.js”charset=”utf-8″></script>

</head>

 

创建down2对象

var downer = new DownloaderMgr();

downer.Config[“Folder”] = “”;//设置默认下载路径。

//挂载事件

downer.event.taskCreate = function (obj) { $(document.body).append(文件ID:” + obj.fileSvr.id) + “<br/>”; };

downer.event.downProcess = function (obj) { };

downer.event.downStoped = function (obj) { };

downer.event.downComplete = function (obj) {

    $(document.body).append(‘<div>本地路径:’ + obj.fileSvr.pathLoc + ‘</div>’);

};

downer.event.downError = function (obj, err) { };

downer.event.queueComplete = function () { $(document.body).append(“<div>队列完成</div>”); };

 

批量下载url

$(“#btn-down-files”).click(function () {

    if (downer.Config[“Folder”] == “”) { downer.open_folder(); return; }

    var urls = [

        { fileUrl: “http://res2.ncmem.com/res/images/ie11.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/up6.1/down.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/firefox.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/edge.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/up6.1/cloud.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/home/w.png” }

        , { fileUrl: “http://res2.ncmem.com/res/images/img.png” }

    ];

    downer.app.addUrls(urls);

});

 

当成一个文件夹下载

$(“#btn-down-json”).click(function () {

    if (downer.Config[“Folder”] == “”) { downer.open_folder(); return; }

    var fd = {

        nameLoc: 图片列表”

        , files: [

            { fileUrl: “http://res2.ncmem.com/res/images/ie11.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/up6.1/down.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/firefox.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/edge.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/up6.1/cloud.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/home/w.png” }

            , { fileUrl: “http://res2.ncmem.com/res/images/img.png” }

        ]

    };

    downer.app.addJson(fd);

});

 

下载多级目录

$(“#btn-down-fd”).click(function () {

    if (downer.Config[“Folder”] == “”) { downer.open_folder(); return; }

    var fd = {

        nameLoc: 测试文件夹”

        , files: [

            { fileUrl: “http://www.ncmem.com/images/ico-ftp.jpg” }

            , { fileUrl: “http://www.ncmem.com/images/ico-up.jpg” }

        ]

        , folders: [

            {

                nameLoc: 图片1″

                , files: [

                    { fileUrl: “http://www.ncmem.com/images/ico-ftp.jpg” }

                    , { fileUrl: “http://www.ncmem.com/images/ico-up.jpg” }

                    , { fileUrl: “http://www.ncmem.com/images/ico-capture.jpg” }

                    , { fileUrl: “http://www.ncmem.com/images/ico-imageuploader.gif” }

                    , { fileUrl: “http://www.ncmem.com/images/ico-wordpaster.gif” }

                ]

                , folders: [

                    {

                        nameLoc: 软件”

                        , files: [

                            { fileUrl: “http://res2.ncmem.com/res/images/edit-file.png” }

                        ]

                    }

                ]

            }

        ]

    };

    downer.app.addJson(fd);

});

 

自定义下载文件名称

$(“#btn-down-svr”).click(function () {

    if (downer.Config[“Folder”] == “”) { downer.open_folder(); return; }

    var urls = [

        { fileUrl: “http://localhost:90/db/down.aspx”, nameLoc: “test.exe” }

        , { fileUrl: “http://localhost:90/db/down.aspx”, nameLoc: “test-1.exe” }

    ];

    downer.app.addUrls(urls);

});

实现效果:

 

 

希望本文所述对大家的asp.net#程序设计有所帮助。

网上示例:http://blog.ncmem.com/wordpress/2019/08/28/net文件批量下载/