node js post request undefined

Question

我是nodejs的新手。我正在收到请求，但是req.body未定义。请提前帮助感谢。

这里是我的代码

Server.js

var express = require('express'), 
app = express(), 
bodyParser = require('body-parser'), 
db = require('./database/database.js'), 
PORT = process.env.PORT || 3000, 
router = express.Router(); 
//Routers 
var userActionsRouter = require('./routes/user-actions.js'); 
var userRouter =  require('./routes/user.js'); 
var transactionRouter = require('./routes/transaction.js'); 
//Routes 
app.use('/api/v2/user_actions/', userActionsRouter); 
app.listen(PORT, function(){ 
    console.log('We are connected'+PORT); 
}) 

路由文件

var express = require('express'), 
router = express.Router(), 
userActionController = require('../controllers/user-actions-controller.js'), 
app = express(); 
//Sign-In 
router.post('/sign_in', userActionController.signIn); 
//Sign-Out 
router.post('/sign_out', userActionController.signOut); 
module.exports = router; 

我的用户行为，controller.js文件

var express = require('express'); 
bodyParser = require('body-parser'); 
app = express(); 
app.use(bodyParser.urlencoded({ extended: false })); 
app.use(bodyParser.json()); 
module.exports.signIn = function(req, res){ 
console.log('params: ' + JSON.stringify(req.params));//{} 
console.log('body: ' + JSON.stringify(req.body));// undefined 
console.log('query: ' + JSON.stringify(req.query));//{} 
console.log("data:" +JSON.stringify(req.data));// undefined 
}) 

Answer 1

添加'content-type'与'application/json';

'content-type': 'application/json'