我正在嘗試創建基本的CRUD應用程序並在調試時遇到問題。要構建我的CRUD應用程序,我正在使用node.js,express和mongodb。任何你可以提供的幫助將會非常有幫助。Express/node.js調試錯誤:發送後無法設置標題
方面:參考我使用這個:
https://zellwk.com/blog/crud-express-mongodb/, currently on "Showing quotes to users"
我的問題:我得到我的代碼下面的錯誤,我不知道這是由於我的代碼的位置。
Error: Can't set headers after they are sent.
at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:357:11)
at ServerResponse.header (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\response.js:725:10)
at ServerResponse.contentType (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\response.js:558:15)
at ServerResponse.send (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\response.js:145:14)
at done (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\response.js:962:10)
at tryHandleCache (C:\Users\hcqph\gitprojects\crudbeta\node_modules\ejs\lib\ejs.js:208:10)
at View.exports.renderFile [as engine] (C:\Users\hcqph\gitprojects\crudbeta\node_modules\ejs\lib\ejs.js:412:10)
at View.render (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\view.js:128:8)
at tryRender (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\application.js:640:10)
at EventEmitter.render (C:\Users\hcqph\gitprojects\crudbeta\node_modules\express\lib\application.js:592:3)
這是我的代碼:
app.use(bodyParser.urlencoded({extended: true}))
//set 'ejs' template engine, and default extension is ejs
app.set('view engine', 'ejs')
/* -------- for team documentation --------
=> = replacement for function
app.get hand a GET request (read operation)
------------------------------------------------ */
app.get('/', (req, res) => {
//serves index.html back to browser
res.sendFile(__dirname + '/index.html')
//gets list of trips from mlab.com
var cursor = db.collection('trips').find()
//retrieves list of trips retrieved from mlab
db.collection('trips').find().toArray(function(err, results) {
if(err) return console.log(err)
//renders index.ejs
res.render('index.ejs', {trips:results})
})
})
/* app.post handles a create request */
app.post('/trips', (req, res) => {
db.collection('trips').save(req.body, (err, result) =>{
if (err) return console.log(err)
console.log('saved to database')
res.redirect('/') //causes browser to reload
})
})
是不是因爲我打我的app.set在哪裏?我怎樣才能解決這個問題?
另外,如果它嵌套在文件夾視圖中,我是否正確引用了我的res.render for index.ejs?
很可能是因爲在'/'端點你調用'res.sendFile'和'res.render'。你不應該爲一個請求發送兩個響應。 –