Nodejs return 函数的结果是空的承诺

Question

我正在尝试使用 Nodejs tron 库创建一对钱包地址，这是我的代码：

app.js

var app = require('express')()
var http = require('http').createServer(app)
var wallet_engine = require('./function')
app.get('/', function (req, res) {
    result = wallet_engine.create_wallet_trx()
    console.log(result)
    res.send(result)
})
//////server listen
http.listen(8443, function () {
    console.log('listening on *:8443')
})

这是我的 function.js

module.exports = {
    create_wallet_trx: function () {
////////generate TRX Address
        var { HdTronPayments } = require('@faast/tron-payments')
        var keys = HdTronPayments.generateNewKeys()
        var tronPayments = new HdTronPayments({ hdKey: keys.xprv })
        var address = tronPayments.getPayport(356)
        var privateKey = tronPayments.getPrivateKey(356)
        var trx_wallet = { privateKey: privateKey, address: address }
        console.log(trx_wallet)
        return trx_wallet
    },
}

问题是当我检查 console.log(trx_wallet) 结果在那里，我可以看到生成的 public 和私钥，同样在返回数据后，console.log(result) 正在显示数据，但 res.send(result) 显示为空 json.

这是 console.log() 结果

{
  privateKey: Promise {
    'B88BB56DAB80DB681765A0C07197DD23BB8E2FAD195BF9D0ECD09F5F8FC54297'
  },
  address: Promise { { address: 'TYCJSKERHReUXacw9wLorZYLDoijevvsVK' } }
}

这是我浏览器上的结果：

{"privateKey":{},"address":{}}

我知道这是因为 Nodejs 异步系统，我应该等待 promise 获取值，但我不知道如何等待 promise 完成，然后在我的浏览器屏幕上打印结果。

Answer 1

你做得很好，但这里有很多调用是异步的，这让你面临问题。你应该像我下面那样使用 async await or then 它可能对你有帮助..

// app js


var app = require('express')()
var http = require('http').createServer(app)
var wallet_engine = require('./function')
app.get('/', function (req, res) {
    result = wallet_engine.create_wallet_trx().then(data=>{
      res.json(data);
    }).catch(err=>{
      console.log(err);
    })
})
//////server listen
http.listen(8443, function () {
    console.log('listening on *:8443')
})



// function.js

var { HdTronPayments } = require('@faast/tron-payments')

module.exports = {
  create_wallet_trx: async function () {
      var keys = await HdTronPayments.generateNewKeys()
      var tronPayments = await new HdTronPayments({ hdKey: keys.xprv })
      var address = await tronPayments.getPayport(356)
      var privateKey = await tronPayments.getPrivateKey(356)
      var trx_wallet = { privateKey: privateKey, address: address }
      return trx_wallet
  }
}

结果：{"privateKey":"92ACAECFE00E9F90E330A6B031F10365F29AFDD503922CC99CA8704F1BA53432","address":{"address":"TGfsHx4VU6B36AwUy8Bqt6edoNnUHpMtSQ"}}

Nodejs return 函数的结果是空的承诺

Nodejs return result from function is empty promise

asynchronous

return

node.js

promise

tron