一般來說瀏覽器要同時下載幾個文件，比如pdf文件，會在服務器端把幾個文件壓縮成一個文件。但是導致的問題就是會消耗服務器的cpu和io資源。
那有沒有辦法，用戶點了幾個文件，在客戶端同時下載呢？ 支持html5的瀏覽器是可以的，html的a標簽有一個屬性download
<a download="下載的1.pdf" href="1.pdf">單個文件下載</a>, 經過測試在edge瀏覽器，firefox和chrome都支持。但是遺憾的是ie瀏覽器不支持。參考下面的例子。
<!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="批量下載" />
<script>
var filesForDownload = [];
filesForDownload[filesForDownload.length] = {
path: "1.zip", //要下載的文件路徑
name: "file1.txt" //下載后要顯示的名稱
};
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瀏覽器怎么辦呢？ 也可以用window.open函數。
<!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="下載的1.pdf" href="1.pdf">單個文件下載</a><br>
<a href="#" class="yourlink">下載全部文件</a>
<script>
$('a.yourlink').click(function(e) {
e.preventDefault();
window.open('1.zip','download');
window.open('2.zip','download');
window.open('3.zip','download');
});
</script>
</body>
</html>
完整的方案就是根據瀏覽器類型，調用不同的函數，實現。
另外要下載pdf，而不是在瀏覽器中打開的話，需要配置apache的配置文件，在httpd.conf中增加下面的配置。
<FilesMatch "\.pdf$">
Header set Content-Disposition attachment
</FilesMatch>
或者使用down2組件，下載更簡單。
JavaScript：
引入頭
<head>
<metahttp-equiv="Content-Type"content="text/html; charset=utf-8"/>
<title>donw2-多文件演示頁面</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>
創建down2對象
var downer = new DownloaderMgr();
downer.Config["Folder"] = "";//設置默認下載路徑。
//掛載事件
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>本地路徑：' + obj.fileSvr.pathLoc + '</div>');
};
downer.event.downError = function (obj, err) { };
downer.event.queueComplete = function () { $(document.body).append("<div>隊列完成</div>"); };
批量下載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);
});
當成一個文件夾下載
$("#btn-down-json").click(function () {
if (downer.Config["Folder"] == "") { downer.open_folder(); return; }
var fd = {
nameLoc: "圖片列表"
, 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);
});
下載多級目錄
$("#btn-down-fd").click(function () {
if (downer.Config["Folder"] == "") { downer.open_folder(); return; }
var fd = {
nameLoc: "測試文件夾"
, files: [
{ fileUrl: "http://www.ncmem.com/images/ico-ftp.jpg" }
, { fileUrl: "http://www.ncmem.com/images/ico-up.jpg" }
]
, folders: [
{
nameLoc: "圖片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: "軟件"
, files: [
{ fileUrl: "http://res2.ncmem.com/res/images/edit-file.png" }
]
}
]
}
]
};
downer.app.addJson(fd);
});
自定義下載文件名稱
$("#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);
});
實現效果：
希望本文所述對大家的asp.net#程序設計有所幫助。
網上示例：http://blog.ncmem.com/wordpress/2019/08/28/net文件批量下載/