如何读取在Node.js的快速后端上Xmlhttprequest POST请求中发送的值？

Question

我想将candid和candidresults的值发送到我的快速后端的/ savevote路由中。我该怎么做。

var candid;
var candidresults;                                                                                                   

 var xhr = new XMLHttpRequest();

xhr.open('POST', 'savevote', true);
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
xhr.onload = function () {

        contractInstance.voteForCandidate(candidateName, {
      from: web3.eth.accounts[0]
    }, function () {
      console.log(contractInstance.totalVotesFor(candidateName).toString());


      candid = candidateName;
      candidresults = contractInstance.totalVotesFor(candidateName).toString();

    console.log(this.responseText);
};
xhr.send(candid);
xhr.send(candidresults);
}

而且，我如何通过我在Express后端下面创建的/ savevote路由访问这些值，如下所示

router.post('/savevote', function (req, res, next) {


});

Answer 1

在您的快递上，您需要使用中间件才能从req.body读取参数

下面是示例代码

const express = require('express')

const app = express()
app.use(express.urlencoded())
app.post('/savevote', (req, res) => {
    res.json({
        msg: "Echo respose"
        candid: req.body.candid,
        candidresults: req.body.candidresults
    })
})

app.listen(3000)

而且，从用户界面中，您无法多次调用xhr.send。只能调用一次，如下所示

xhr.send("foo=bar&lorem=ipsum");