我的错误是：错误 [ERR_HTTP_HEADERS_SENT]：发送给客户端后无法设置 headers

Question

我试图在车把文件中输出 result，当我运行服务器时，一切都运行完美，但是当我检查浏览器时，它显示 [object Object] 然后在控制台中写入以下错误：Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client

问题是什么，我该如何解决？

const express = require('express');
var exphbs  = require('express-handlebars');
var http = require("http");
const net  = require('net');
const Web3 = require('web3');
var app = express();

app.engine('handlebars', exphbs({defaultLayout: 'layout'}));
app.set('view engine', 'handlebars');

const web3 = new Web3(new Web3.providers.IpcProvider("/home/terry/.ether1/geth.ipc",net))
console.log(web3.isConnected()) // return true if connected

web3.version.getNetwork((error, result) => {
    console.log('The result is: ' + result)
});

app.get('/', function (req, res, result) {
    res.render('index',{
        title: result
    });
});

app.listen(50000)
console.log('Server running at http://127.0.0.1:50000/');

我希望 title: result 以其应有的方式输出，而不是 [object Object]

Answer 1

result 在这个函数中：function (req, res, result) 不是结果它是 next() 函数你不能像这样使用它

尝试这样的事情

app.get('/', function (req, res, next) {
    web3.version.getNetwork((error, result) => {
     res.render('index',{
        title: result
     });
    });

});

我的错误是：错误 [ERR_HTTP_HEADERS_SENT]：发送给客户端后无法设置 headers

My error is: Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client

node.js

handlebars.js

web-development-server