程序按原样运行,直到我再次尝试使用该函数并返回错误:发送后无法设置标头。
我正在创建这个应用程序以熟悉nodejs和javascript,我一直在阅读有关错误的信息,并且在向请求发送多个响应时似乎是一个问题。在开始知道这个之前我开始使用res.setHeader,但我读到res.header可以避免这个问题,它没有解决它,但我保留了它。
HTML:
<!doctype html>
<head>
<link rel="stylesheet" type="text/css" href="youtube2music.css">
<title>
Youtube2Music
</title>
</head>
<body>
<div id="cabeza">
<h1>
Youtube 2 Music
</h1>
<p>
just paste your link below and download your song.
</p>
</div>
<div id="down-part">
<input id="myUrl" class='myUrl-input'>
</input>
<button type="button" class="download_button">
Download
</button>
</div>
</body>
<script src='youtube2music.js'></script>
</html>
使用Javascript:
var urlinput = document.querySelector('.myUrl-input'); // gets url inputbox
var button = document.querySelector('.download_button'); // gets download button
button.addEventListener('click', () => {
console.log(urlinput.value); // prints in console the url
sendUrl(urlinput.value); // sends url to function to start the request
});
// function to make requst
function sendUrl(URL){
window.location.href = `http://localhost:4000/?URL=${URL}`; // makes the video request to nodejs server
}
index.js <node file:
var eventEmitter = new events.EventEmitter();
var sfn;
appi.use(cors());
const {app, BrowserWindow} = require('electron')
function createWindow(){
let win = new BrowserWindow({width:800, height:600});
win.loadFile('index.html');
}
app.on('ready', createWindow)
appi.listen(4000, () => {
console.log('server at port 4000');
});
appi.get('/',(req,res)=>{
var URL = req.query.URL;
ytdl.getInfo(URL, function(err,info){
if(err) throw err;
var songTitle = info.title;
sfn = filenamify(songTitle);
eventEmitter.emit('name_ready');
});
var startDownload = function(){
let stream = ytdl(URL, {
quality: 'highestaudio',
});
res.header('Content-Disposition', 'attachment; filename=' + sfn + '.mp3');
res.header('Content-type', 'audio/mpeg');
proc = new ffmpeg({source: stream})
proc.withAudioCodec('libmp3lame').toFormat('mp3').output(res).run();
}
eventEmitter.on('name_ready', startDownload);
})
因为它适用于第一个输入,但要求另一个输出导致错误,为什么它真的返回此错误,如何避免?
您当前的设置存在几个问题:
appi.listen(4000, () => {
console.log('server at port 4000');
});
appi.get('/', (req,res)=> {
const { URL } = req.query;
ytdl.getInfo(URL, (err,info) => {
if(err) throw err;
const songTitle = info.title;
const sfn = filenamify(songTitle);
let stream = ytdl(URL, {
quality: 'highestaudio',
});
res.set('Content-Disposition', 'attachment; filename=' + sfn + '.mp3');
res.set('Content-type', 'audio/mpeg');
const proc = new ffmpeg({source: stream})
proc.withAudioCodec('libmp3lame').toFormat('mp3').output(res).run();
});
})