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
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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
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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});
}
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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。
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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
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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。
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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);
}
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Angular And Contentful - Content Management For Single-Page Web Apps https://www.youtube.com/watch?v=KhmjLjvlmyQ
Contentful官网： https://www.contentful.com
