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>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1">
<title></title>
<script src="//libs.baidu.com/jquery/1.11.1/jquery.min.js"></script>
</head>
<body>
<input type="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>
<meta charset="utf-8">
<title></title>
<script src="//libs.baidu.com/jquery/1.11.1/jquery.min.js"></script>
</head>
<body>
<a download="下载的1.pdf" href="1.pdf">单个文件下载</a><br>
<a href="#" 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。