• Angular45


    Angular 4 Tutorial for Beginners: Learn Angular 4 from Scratch     https://www.youtube.com/watch?v=k5E2AVpwsko&list=PLTjRvDozrdlxAhsPP4ZYtt3G8KbJ449oT
    安装Angular CLI: npm install -g @angular/cli   安装之后输入ng --version检查版本.
    创建新项目: ng new hello-world
    打开vs code, 快捷键ctrol+shift+p,输入code选择Shell Command:Install 'code' command in PATH, 输入code .(code后面空格然后是点)
    ng server 启动项目
    
    安装typescript: npm install -g typescript
    
    javascript中var声明的变量在它所属最近的方法中都有效.e.g.
    function doSomething(){
        for(var i=0;i<5;i++){
            console.log(i);
        }
        console.log('Finally: '+i);  //注意这里的i也是有效的, 如果用typescript中的let定义变量i,则这里的i无效.
    }
    
    强类型转换: 
    let endsWithC=(<string>message).endsWith('c');
    let endsWithC=(message as string).endsWith('c');
    
    typescript中方法的写法:
    let doLog=(message) => {console.log(message);} 类似于c#中的lamda写法.
    
    typescript不能含有多个构造函数, 如果需要实例化不带参数的对象,则设置参数为nullable.e.g.
    constructor(x?: number, y?: number){
        this.x=x;
        this.y=y;
    }
    
    上面的写法在typescript中可以简化为:
    constructor(public x?:number, private y?:number){
    
    }
    
    变量前可以加private,public, protected修饰, 默认的是public.
    
    属性的例子:
    变量x是私有的,
    get X(){
        return this.x;
    }
    
    set X(value){
        if(value<0) throw new Error(''value cannot be less than 0.);
        this.x=value;
    }
    使用: let x=point.X;
    point.X=10;
    
    取名: course-4.component.ts
    --------------------------------------------------------------------------------------------------------------------------------------------------------
    Angular 4 - The Basics (Udemy Course Excerpt)     https://www.youtube.com/watch?v=htPYk6QxacQ
    安装Bootstrap命令:  npm install --save bootstrap
    打开.angular-cli.json文件,在"style"节点下添加"../node_modules/bootstrap/dist/css/bootstrap.min.css"
    
    selector:'app-servers' //元素
    selector:'[app-servers]'  //属性
    selector:'.app-servers'  //类,不支持id
    
    TODO: 1:10:0
    
    
    -----------------------------------------------------------------------------------------------------------------------------------------------------
    Angular 5 Tutorial - 1 - Introduction     https://www.youtube.com/watch?v=0eWrpsCLMJQ&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ
    version 1.2.3  各数字分别表示  Major, Minor, Fix(Patch)
    检查版本:node -v, npm -v, ng -v(angular cli的版本)
    AngularCLI官网: https:cli.angular.io   安装命令:npm install -g @angular/cli
    
    Angular 5 Tutorial - 3 - Hello World App   https://www.youtube.com/watch?v=mDoHtD1hI3I&index=3&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ
    ng new hello-world --routing
    cd hello-world
    ng serve = npm start
    
    selector的三种方式: 'app-test','.app-test','[app-test]', 对应的html为<app-test></app-test>,<div class="app-test"></div>,<div app-test></div>
    
    Angular 5 Tutorial - 6 - Property Binding   https://www.youtube.com/watch?v=N8FBmB2jme8&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=6
    Attribute vs Property
    Attribute - HTML
    Properties - DOM (Document Object Model)
    Attribute的值不变, Property的值可变.
    
    Property Binding: [disabled]="isDisabled"  //1.左侧是[],2.右侧"",3.isDisabled是bool类型.
    也可以写成:bind-disabled="isDisabled"
    
    [class.text-danger]="hasError" //如果hasError为true则应用样式text-danger,否者不用
    多条件: <h2 [ngClass]="messageClasses">Something</h2> //1.[ngClass] 2.messageClassess属性包括多个条件
    
    <h2 [style.color]="highlightColor">Style Binding</h2> //highlightColor是Property
    <h2 [style.color]="'red'">Style Binding</h2>  //'red'
    <h2 [style.color]="hasError ? 'red' : 'gree'">Style Binding</h2>
    多条件: <h2 [ngStyle]="titleStyles">Style Binding 3</h2>  //titleStyles里面有多个样式设定
    
    Angular 5 Tutorial - 9   https://www.youtube.com/watch?v=ZfIc1_oj7uM&index=9&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ
    (click) = "onClick($event)" //带event参数
    (click) = "greeting='Hello World'"  //直接执行
    
    <input #myInput type="text">
    <button (click)="logMessage(myInput.value)">Log</button>
    
    双向绑定需要在app.module.ts中导入FormsModule
    [(ngModel)]="name" 
    
    *ngIf="isVisible" //不会显示dom元素
    
    Angular中的if else:
    方法一:
    <h2 *ngIf="displayName; else elseBlock">
        Codevolution
    </h2>
    
    <ng-template #elseBlock>
        <h2>
            Name is hidden
        </h2>
    </ng-template>    
    方法二:
    <div *ngIf="displayName; then thenBlock; else elseBlock"></div>
    
    <ng-template #thenBlock>
        <h2>aaa</h2>
    </ng-template>        
    
    <ng-template #elseBlock>
        <h2>bbb</h2>
    </ng-template>        
    
    Angular中的Switch:
    <div [ngSwitch]="color">
        <div *ngSwitchCase="'red'">You picked red color</div>
        <div *ngSwitchCase="'blue'">You picked blue color</div>
        <div *ngSwitchCase="'green'">You picked green color</div>
        <div *ngSwitchDefault>Pick again</div>
    </div>    
    
    Angular中的for:
    <div *ngFor="let color of colors; index as i">
        <h2>{{i}} {{color}}</h2>
    </div>    
    
    Angular 5 Tutorial - 15 - Component Interaction  https://www.youtube.com/watch?v=BGy8DdGw_WE&list=TLGG0JkcZDBvWZcxODEyMjAxNw
    Parent > Child
    app.component.html: <app-test [parentData]="name"></app-test>
    test.component.ts: 
    import {Input} from '@angular/core';  //导入命令空间Input
    @Input() public parentData;  //@Input修饰符表示这个属性是从父控件传过来的, 别名的写法: @Input('parentData') public name;
    
    Parent > Child
    test.component.ts:
    import {Output,EventEmitter} from '@angular/core';  //导入命令空间
    @Output() public childEvent = new EventEmitter();
    
    <button (click)="fireEvent()">Send Event</button>
    fireEvent(){
        this.childEvent.emit('Hello World');
    }
    
    app.component.html: <app-test (childEvent)="message=$event"></app-test> //这里的$event就是子组件中传过来的值'Hello World'
    
    Angular 5 Tutorial - 16 - Pipes   https://www.youtube.com/watch?v=y8lwG8IM82k&index=2&list=TLGG0JkcZDBvWZcxODEyMjAxNw
    {{name | slice:3:5}} //显示从第三个字符开始到第五个字符(不包括)之间的字符
    {{person | json}}
    {{5.678 | number:'3.1-2'}}  //3表示小数点的左边显示三位数,1-2表示小数点的右边显示最少一位最多两位数,最后显示005.67
    {{0.25 | currency}} //显示$0.25
    {{0.25 | currency: 'GBP'}}  //显示英镑
    {{date | date:'short'}}
    {{date | date:'shortDate'}}
    {{date | date:'shortTime'}}
    
    Angular 5 Tutorial - 21 - Fetch Data Using HTTP  https://www.youtube.com/watch?v=LmIsbzt-S_E&index=21&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ
    ng g s employee 创建employee.service.ts
    app.module.ts:
    import {HttpClientModule} from '@angular/common/http';  //Angular5使用HttpClient而不是之前的Http
    imports:[HttpClientModule]
    employee.service.ts:
    import {HttpClient} from '@angular/common/http';
    constructor(private http:HttpClient){}
    getEmployees():Observable<IEmployee[]>{ //需要指定返回结果为Observable<IEmployee[]>
        return this.http.get<IEmployee[]>(this._url);
    }
    
    Angular 5 Tutorial - 22 - HTTP Error Handling  https://www.youtube.com/watch?v=TmTGQiLBS5A&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=22
    import 'rxjs/add/operator/catch';
    import 'rxjs/add/observable/throw';
    getEmployees():Observable<IEmployee[]>{ 
        return this.http.get<IEmployee[]>(this._url)
        .catch(this.errorHandler);
    }
    errorHandler(error: HttpErrorResponse){
        return Observable.throw(error.message || "Server Error");
    }
    
    使用: this._employeeService.getEmployees().subscribe(data=>this.employees=data, error=>this.errorMsg=error);
    
    Angular 5 Tutorial - 23 - Routing and Navigation  https://www.youtube.com/watch?v=Nehk4tBxD4o&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=23
    ng new routing-demo --routing  //创建带router的项目
    
    如何在现有项目中添加router:
    src/index.html: <base href="/">
    添加app/app-routing.module.ts文件,导入到app.module.ts中.
    
    ng g c department-list -it -is  //创建component
    
    配置app-routing.module.ts:
    export const routingComponents = [DepartmentListComponent, EmployeeListComponent], 导入到app.module.ts中. 之后有新的components只需要添加到app-routing.module.ts文件中.
    
    <a routerLink="/departments" routerLinkActive="active">Departments</a>
    <a routerLink="/employees" routerLinkActive="active">Employees</a>
    
    npm start 启动项目, 打开localhost:4200
    
    Angular 5 Tutorial - 24 - Wildcard Route and Redirecting Routes   https://www.youtube.com/watch?v=QC6wRxXT26I&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=24
    ng g c page-not-found -it -is   //创建component
    
    app-routing.module.ts中添加:
    {path:'', redirectTo:'/departments', pathMatch:'full'}  //放在最前,对应地址localhost:4200
    {path:"**", component: PageNotFoundComponent}  //page not found必须放在最后
    
    Angular 5 Tutorial - 25 - Route Parameters  https://www.youtube.com/watch?v=qh5nHv-4aw0&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=26
    页面跳转, app-routing.module.ts:
    import {DepartmentDetailComponent} from './department-detail/department-detail.component';
    const routes:Routes=[
    {path:'department/:id',component:DepartmentDetailComponent}
    ];
    export const routingComponents=[DepartmentDetailComponent]
    
    department-list.component.ts:
    import {Router} from '@angular/router';
    constructor(private router: Router){}
    onSelect(department){
        this.router.navigate(['/departments',department.id]);
    }
    
    
    读取url中传过来的参数. department-detail.component.ts:
    import {ActivatedRoute} from '@angular/router';
    constructor(private route: ActivatedRoute){}
    ngOnInit(){
        let id = parseInt(this.route.snapshot.paramMap.get('id'));
        this.departmentId = id;
    }
    
    Angular 5 Tutorial - 26 - paramMap Observable  https://www.youtube.com/watch?v=KRV9jZwl0Ig&index=25&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ         
    route.snapshot有个缺点,当跳转到同一个component只是参数有变化的时候,页面里面获取的参数值不会改变. 这时需要使用route.paramMap来监视参数的变化:
    import {ParamMap} from 'angular/router';
    ngOnInit(){
        //let id = parseInt(this.route.snapshot.paramMap.get('id'));
        //this.departmentId = id;
        this.route.paramMap.subscribe((params:ParamMap)=>{        
            let id = parseInt(params.get('id'));
            this.departmentId = id;
        });
    }
    
    Angular 5 Tutorial - 27 - Optional Route Parameters  https://www.youtube.com/watch?v=gnTFkl2AF-w&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=27
    用于跳转回原地址,回到参数所代表的tab等
    gotoDepartments(){
        let selectedId = this.departmentId ? this.departmentId : null;
        this.router.navigate(['/departments',{id: selectedId}]);  //点击返回按钮跳转到地址 localhost:4200/departments;id=1, 这里的;id=1即是可选参数
    }
    读取可选参数id的值:
    import {Router,ActivatedRoute,ParamMap} from '@angular/router';  
    constructor(private router: Router, private route: ActivatedRoute){}
    public selectedId;
    ngOnInit(){
        this.route.paramMap.subscribe(()=>{
            let id = parseInt(params.get('id'));
            this.selectedId=id;
        });
    }
    
    Angular 5 Tutorial - 28 - Relative Navigation  https://www.youtube.com/watch?v=qktmk-7Kot8&index=28&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ  
    this.router.navigate(['/departments', department.id]);  //绝对路径
    this.router.navigate([department.id],{relativeTo: this.route});  //相对路径的写法,department-list.component.ts中
    this.router.navigate(['../',{id:selectedId}],{relativeTo: this.route});  //department-detail.components.ts中
    
    Angular 5 Tutorial - 29 - Child Routes  https://www.youtube.com/watch?v=ZoeZxpfTCXk&list=PLC3y8-rFHvwhBRAgFinJR8KHIrCdTkZcZ&index=29  //看完等更新
    app-routing.module.ts:
    {
        path:'departments/:id',
        component:DepartmentDetailComponent,
        children:[
            {path:'overview', component: DepartmentOverviewComponent},
            {path:'contact', component: DepartmentContactComponent}
        ]
    }
    //添加到routingComponents数组中
    export const routingComponents = [DepartmentOverviewComponent,DepartmentContactComponent]
    
    department-detail.component.ts:
    <p>
        <button (click)="showOverview()">Overview</button>
        <button (click)="showContact()">Contact</button>
    </p>
    <router-outlet></router-outlet>
    showOverview(){
        this.router.navigate(['overview'],{relativeTo: this.route});
    }
    showContact(){
        this.router.navigate(['contact'],{relativeTo: this.route});
    }
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    -----------------------------------------------------------------------------------------------------------------------------------------------------
    Deploy An Angular App To Firebase In Minutes     https://www.youtube.com/watch?v=mF7FTWHS3ys
    用windows自带的命令窗口,不要用Gitbash.
    打开firebase console页面: https://console.firebase.google.com/ 点击项目 > Hosting > Get started......
    
    Javascript中的闭包:
    Javascript语言的特殊之处,就在于函数内部可以直接读取全局变量。
    另一方面,在函数外部自然无法读取函数内的局部变量。  这里有一个地方需要注意,函数内部声明变量的时候,一定要使用var命令。如果不用的话,你实际上声明了一个全局变量!
    如何从外部读取局部变量?那就是在函数的内部,再定义一个函数。
    函数带()才是执行函数!
    由于在Javascript语言中,只有函数内部的子函数才能读取局部变量,因此可以把闭包简单理解成“定义在一个函数内部的函数”。
    闭包可以用在许多地方。它的最大用处有两个,一个是前面提到的可以读取函数内部的变量,另一个就是让这些变量的值始终保持在内存中。
    ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    Use Babel & Webpack To Compile ES2015 - ES2017   https://www.youtube.com/watch?v=iWUR04B42Hc
    babel_webpack_starter: https://github.com/bradtraversy/babel_webpack_starter
    webpack: https://webpack.github.io/docs/what-is-webpack.html
    Babel: https://babeljs.io
    
    npm init //创建package.json文件,scripts下添加"build":"webpack", "start":"webpack-dev-server --output-public-path=/build/"
    npm install --save-dev webpack webpack-dev-server babel-core babel-loader babel-preset-env
    创建webpack.config.js
    npm run build //编译
    npm start //启动webpack-dev-server就不需要执行npm run build了, 它会一直监视修改不需要刷新页面.
    
    异步方法:
    async function getPosts(){
        const response=await fetch('https://jsonplaceholder.typicode.com/posts');
        const data=await response.json();
        return data;
    }
    getPosts().then(posts=>console.log(posts));
    npm install --save-dev babel-polyfill babel-preset-stage-0
    修改webpack.config.js
    --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    01 Blank App In Visual Studio 2017  https://www.youtube.com/watch?v=2VIVOJsKrTI&list=PL2yYLRgebbHakhdiCZkykZQU0CQer3pvO
    创建Empty的asp.net core项目, NuGet安装Microsoft.AspNetCore.StaticFiles
    安装WebPack Task Runner 网址https://marketplace.visualstudio.com/items?itemName=MadsKristensen.WebPackTaskRunner, 打开 Task Runner Explorer 面板.
    Add New Item > npm Configuration File 创建package.json并修改
    Visual Studio的命令窗口是Pacage Manager Console.
    package.json文件右键选择Restore Packages,相当于执行命令npm install
    
    Add New Item > TypeScript JSON Configuration File 创建 tsconfig.json文件并修改
    Add New Item > WebPack Configuration File 创建 webpack.config.js文件并修改
    
    index.ts文件中export所有的component和module.
    import * as Barrel from '*'; //导入index.ts
    
    执行AngularCLI命令编译Angular程序: npm build
    在开发的过程中,我们会用到AngularCLI命令中的 ng serve 命令来启用Angular的监控服务模式。他会监控Angular的源码变化,当源码被改变时,自动重新编译Angular程序并编译TypeScript代码。默认情况下ng serve提供的是localhost:4200地址。
    -----------------------------------------------------------------------------------------------------------------------------------------------------
    Angular 4 CRUD With Web API   https://www.youtube.com/watch?v=Ous6v0r7kXc
    Add New Item > 左侧Data下的ADO.NET Entity Data Model取名DBModels
    Add Controller > Web API 2 Controller with actions, useing Entity Framework  //仔细看下生成的代码,很有借鉴性.
    后台Post方法中不需要if(!ModelState.IsValid),所有的验证在angular中.
    
    ng new angularCURD  //创建angular项目
    cd angularCURD
    ng serve --open  //启动服务并打开浏览器localhost://4200
    生成的.spec.ts文件是用于测试的,可以删除.
    ng g class employee.model 生成employee.model.ts文件.
    app-emplloyees按下tab键,生成<app-emplloyees></app-emplloyees>
    h2.jumbotron.bg-secondary.text-white按下tab键,生成<h2 class="jumbotron bg-secondary text-white"></h2>   //多个class之间用.
    <input class="form-control" name="Office" #Office="ngModel" [(ngModel)]="employee" />  //#Office="ngModel"用于验证
    
    解决webapi跨域访问的问题: 安装组件Microsoft.AspNet.WebApi.Cors, 地址 https://www.nuget.org/packages/Microsoft.AspNet.WebApi.Cors ,命令是Install-Package Microsoft.AspNet.WebApi.Cors -Version 5.2.3 (或者Install-Package Microsoft.AspNet.WebApi.Cors) 之后代码:
    using System.Web.Http.Cors;
    [EnableCors(origins: "http://localhost:4200",headers:"*",methods:"*")]    //加到public class EmployeeControler: ApiController之上
    上面是针对指定controller, 加到WebApiConfig.cs文件的Register方法下可以针对整个项目有效.
    页面报错的话执行代码Install-Package Microsoft.AspNet.WebApi.Core -Version 5.2.3
    
    安装toastr插件: npm install ngx-toastr --save, 地址https://www.npmjs.com/package/ngx-toastr,
    .angular-cli.json中的"styles"节点下添加"../node_modules/ngx-toastr/toastr.css"
    app.modules.ts中:
    import {ToastrModule} from 'ngx-toastr';
    imports:[
        ToastrModule.forRoot()
    ]
    emplloyees.component.ts中:
    import {ToastrService} from 'ngx-toastr'
    constructor(private toastr:ToastrService)
    this.toastr.success('New Record Added Successfully','Employee Register')
    
    showForEdit(emp: Employee)
    {
        this.employeeService.selectedEmployee = Object.assign({},emp);
    }
    -----------------------------------------------------------------------------------------------------------------------------------------------------
    Angular And Contentful - Content Management For Single-Page Web Apps   https://www.youtube.com/watch?v=KhmjLjvlmyQ
    Contentful官网: https://www.contentful.com
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  • 原文地址:https://www.cnblogs.com/cw_volcano/p/8854784.html
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