小编cot*_*riv的帖子

谁曾尝试过关于Docker Swarm的本教程？

https://docs.docker.com/get-started/part4/

有一节叫做:创建一个集群.我想要做的是使用docker-machine创建几个VM.因为我使用ubuntu16.0.4所以我使用以下命令来获取VirtualBox.

sudo apt-get update
sudo apt-get install virtualbox-5.2

安装VirtualBox后,输入如下命令:

docker-machine create --driver virtualbox myvm1

但它说: sudo:docker-machine:命令未找到

所以我输入另一个命令来检查我是否正确安装了VirtualBox.

sudo virtualbox版本

这将打开Oracle VM VirtualBox Manager,这意味着我确实安装了VirtualBox,但不确定.

谁能帮助我找到合适的解决方案？任何帮助,将不胜感激.

cities: Observable<any>;


this.cities = this.fsProvider.collection('cities').map(cities => {
    return cities.map(city => {
      city.country = this.fsProvider.doc(`countries/${city.country_id}`);
      return city;
    });
});

city包括country信息作为Observable数据.所以,如果我city作为一个传递到另一个页面navParam,只是this.navCtrl.push(AnotherPage, {city: city}),我无法获得国家信息AnotherPage.

我刚刚在这里添加了演示:https://stackblitz.com/edit/ionic-firestore.

欢迎任何想法.

它不喜欢的部分是ngOnInit()中的get()方法.是的,"[ts]属性'get'在类型'AngularFirestoreDocument <{}>'上不存在."

我查看了这里:https://firebase.google.com/docs/firestore/query-data/get-data ,它显示了对单个文档使用get()方法,但它只是不喜欢我的方法？

import { Component, OnInit, Pipe } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { Router, ActivatedRoute } from '@angular/router';

import { AngularFirestore, AngularFirestoreCollection, AngularFirestoreDocument } from 'angularfire2/firestore';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map';

import { User } from './user';

@Component({
   selector: 'user-form',
   templateUrl: 'user-form.component.html'
})
export class UserFormComponent implements OnInit {
form: FormGroup;
title: string;
user = new User();
id;
userDoc: AngularFirestoreDocument<User>;
singleUser: Observable<User>;      

constructor(fb: FormBuilder, …

代码如下:

    import { Component } from '@angular/core';
    import { NavController, Platform } from 'ionic-angular';
    import { TranslateService } from '@ngx-translate/core';
    import { BarcodeScanner } from '@ionic-native/barcode-scanner';

    @Component({
        selector: 'page-home',
        templateUrl: 'home.html'
    })
    export class HomePage {
        constructor(public navCtrl: NavController, private translate: TranslateService, private barcodeScanner: BarcodeScanner) {

        }
        //Switch language 
       changelanguage() {
            let browserLang = this.translate.currentLang;
            this.translate.use(browserLang.match(/en/) ? 'zh' : 'en');
        }
        //Scan test
        ScanCode() {
            this.barcodeScanner.scan()
                .then((result) => {
                    console.log(result);
                })
                .catch((error) => {
                    alert(error);
                });
        }
    }

错误图片:

参考: …