Node.js Can'；在express中发送头后设置头时出错

我有以下3个文件。我的错误是“发送邮件后无法设置邮件头”。我已经看到了，但我无法确定是哪个函数或回调导致在发送头后写入头。我在这上面花了很多时间。请帮忙

routes.js

"use strict";
var controller = require("./controller");

module.exports = function(app){

  app.post('/master', function(req, res) {
    controller.process(req, function(err, data) {
      if( err ) { 
        return res.sendStatus(400);
      } else {
         res.sendStatus(200);
        }
    });// cb ends here
  });// process ends here
}// route ends here

controller.js

module.exports.process = function(req, cb){
  var jsonBody = req.body;
  var type = jsonBody["strType"]; 
  var id = jsonBody["id"];
  var moment = require('moment');

  if ( !type || !id ) {
    return (cb(true, false));
  }

  if( type === "company" ) {
    Company_strCode = jsonBody["Company_strCode"];  
    jsonBody.lastUpdate = moment().format();
    delete jsonBody["strType"];
    delete jsonBody["id"];
    dbOps.companyUpsert(type, Company_strCode, jsonBody, cb);
    dbOps.normalUpsert(type, id, jsonBody, cb);
    return;
  }

  jsonBody.lastUpdate = moment().format();
  delete jsonBody["strType"];
  delete jsonBody["id"];

  dbOps.normalUpsert( type, id, jsonBody, cb );
} //fnProcess ends  

dbOps.js

"use strict";
var keyDef = require('../config/config.json')

var MongoClient = require('mongodb').MongoClient;
var host = keyDef.mongodb.host; 
var port = keyDef.mongodb.port;
var db = keyDef.mongodb.db;
var username = keyDef.mongodb.username;
var password = keyDef.mongodb.password;
var url = "mongodb://"+host+":"+port+"/"+db;

module.exports.normalUpsert = function(type, id, jsonBody, cb){

    MongoClient.connect(url, function(err, db){
        if(err){
            console.log("Mongodb connection error..");
            return cb(true, false);
        }

        db.collection(type).update({"_id":id},{$set:(jsonBody)}, {upsert:true}, function(err){
            if(err){
                return cb(true, false);
            }
            cb(false, true);
        });//func callback
    });// mongoClient callback
};

module.exports.companyUpsert = function(type, Company_strCode, jsonBody, cb){

    MongoClient.connect(url, function(err, db) {
        if(err){
            console.log("Mongodb connection error..");
            return cb(true, false);
        }
        db.collection("Cinema").update({"Cinema_strCompanyCode":Company_strCode},{$set:{"tblCompany":jsonBody}}, {upsert:true}, function(err){
            if(err){
                return cb(true, false);
            }
            cb(false, true);
        });//func callback
    });// mongoClient callback
};

在您的

if（type==“company”）

条件中，您调用cb 2次，导致res.sendStatus一口井调用2次。尝试这样的解决方法，如果它适合你

module.exports.process = function(req, cb){
  var jsonBody = req.body;
  var type = jsonBody["strType"]; 
  var id = jsonBody["id"];
  var moment = require('moment');

  if ( !type || !id ) {
    return (cb(true, false));
  }

  if( type === "company" ) {
    Company_strCode = jsonBody["Company_strCode"];  
    jsonBody.lastUpdate = moment().format();
    delete jsonBody["strType"];
    delete jsonBody["id"];
    dbOps.companyUpsert(type, Company_strCode, jsonBody, function (err, data){
      if (err)
        return (cb(true, false));
      else
        dbOps.normalUpsert(type, id, jsonBody, cb);
    });
    return;
  }

  jsonBody.lastUpdate = moment().format();
  delete jsonBody["strType"];
  delete jsonBody["id"];

  dbOps.normalUpsert( type, id, jsonBody, cb );
} //fnProcess ends  

或者我更喜欢这样的东西：

module.exports.process = function(req, cb){
  var jsonBody = req.body;
  var type = jsonBody["strType"]; 
  var id = jsonBody["id"];
  var moment = require('moment');

  if ( !type || !id ) {
    return (cb(true, false));
  }

  jsonBody.lastUpdate = moment().format();
  delete jsonBody["strType"];
  delete jsonBody["id"];

  if( type === "company" ) {
    Company_strCode = jsonBody["Company_strCode"];  
    dbOps.companyUpsert(type, Company_strCode, jsonBody, function (err, data){
      if (err)
        return (cb(true, false));
    });
  }

  dbOps.normalUpsert( type, id, jsonBody, cb );
} //fnProcess ends 

---

您不需要在控制器中返回标记，只需使用不带返回标记的回调函数即可！不要在控制器的任何地方使用返回标记，只要使用回调函数！！