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=(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,
,


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: 
Something
 //1.[ngClass] 2.messageClassess属性包括多个条件

Style Binding
 //highlightColor是Property
Style Binding
  //'red'
Style Binding
多条件: 
Style Binding 3
  //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


Log

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:

    Codevolution



    

        Name is hidden
    
    
方法二:



    
aaa
        


    
bbb
        

Angular中的Switch:

    
You picked red color
    
You picked blue color
    
You picked green color
    
Pick again
    

Angular中的for:

    
{{i}} {{color}}
    

Angular 5 Tutorial - 15 - Component Interaction  https://www.youtube.com/watch?v=BGy8DdGw_WE&list=TLGG0JkcZDBvWZcxODEyMjAxNw
Parent > Child
app.component.html: 
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();

Send Event
fireEvent(){
    this.childEvent.emit('Hello World');
}

app.component.html:  //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{ //需要指定返回结果为Observable
    return this.http.get(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{ 
    return this.http.get(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: >
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.

"/departments" routerLinkActive="active">Departments
Employees

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:

    Overview
    Contact


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
h2.jumbotron.bg-secondary.text-white按下tab键,生成
   //多个class之间用.
  //#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

 

转载于:https://www.cnblogs.com/cw_volcano/p/8854784.html