文件结构
1、app.js相关文件引入
const koa = require('koa'); // "koa": "^2.2.0"
const app = new koa();
const router = require('koa-router')(); // "koa-router": "^7.2.0"
const send = require('koa-send'); // "koa-send": "^4.1.0"
router.get('/', async function (ctx) {
var fileName = 'index.html';
await send(ctx, fileName, { root: __dirname + '/public' });
});
router.get('/download', async function (ctx) {
// 为了方便演示，这里直接下载index页面
var fileName = 'index.html';
// Set Content-Disposition to "attachment" to signal the client to prompt for download.
// Optionally specify the filename of the download.
// 设置实体头（表示消息体的附加信息的头字段）,提示浏览器以文件下载的方式打开
// 也可以直接设置 ctx.set("Content-disposition", "attachment; filename=" + fileName);
ctx.attachment(fileName);
await send(ctx, fileName, { root: __dirname + '/public' });
});
app
.use(router.routes())
.use(router.allowedMethods());
app.listen(3000);
2、测试页面代码: index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>__小简__下载测试</title>
<style>
div {
width: 100%;
text-align: center;
margin-top: 50px;
}
</style>
<script>
window.onload=function(){
var oBtnDownload=document.getElementById('download');
oBtnDownload.onclick=function(){
window.open('http://localhost:3000/download', '_blank')
}
}
</script>
</head>
<body>
<div>
<button id="download">点击下载</button>
</div>
</body>
</html>
2、测试开始：浏览器打开http://localhost:3000/
点击下载就可以看到效果了
效果图
