进入各demo项目下执行：
cnpm i
ng serve --open
*ngfor
*ngIf
插值表达式 {{}}
属性绑定 []
事件绑定 ()
//数据双向绑定
[(ngModel)]="hero.name"
app.routing注入；
import { Routes, RouterModule } from '@angular/router'
import { Observable, of, } from 'rxjs';
import { catchError, map, tap ,switchMap,distinctUntilChanged,debounceTime,combineLatest} from 'rxjs/operators'; const routes: Routes = [
{ path: '**', redirectTo: '/dashboard', pathMatch: 'full' },
{ path: 'heroes', component: HeroesComponent },
{ path: 'dashboard', component: DashboardComponent },
{ path: 'detail/:id', component: HeroDetailComponent
children:[{ //二级路由配置
path:'/stores',
component:StoreDetailComponent
}]
},
];获取参数的页面引入并且注入：
import { ActivatedRoute ,Router} from '@angular/router'
import { Location } from '@angular/common';
constructor(
private route: ActivatedRoute,
private router: Router,
private heroService: HeroService,
private location: Location
) {}
this.location.back();//返回上一页
this.router.navigateByUrl(path:string) //js实现跳转到指定路径之后再this.route里面即可获取需要的路由信息
let obsCombined = Observable.combineLatest(this.route.params, this.route.queryParams, (params, qparams) => ({
params,
qparams
}));
obsCombined.subscribe(ap => {
console.log(ap);
let params = ap['params'];
let qparams = ap['qparams'];
alert(qparams['title']);
alert(params['id']);
});获取id举例：
this.route.paramMap.subscribe(params => {
let id = params.get('productId');
} <a routerLink='/sharing' skipLocationChange="false">需要在app.module中加入ReactiveFormsModule模块
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
imports: [
FormsModule,
ReactiveFormsModule
]响应式表单html结构 注意点：
[formGroup]处写上表单名称
响应式表单中的每个控件都必须要有自己的formControlName，而且不能加上双向绑定[(ngModel)]
(ngModelChange)事件会在控件值发生改变时触发，参数$event实际为改变后的值
如果控件需要要验证信息，则要在控件的html后面加上nz-form-explain标签，里面写具体的错误提示
<form nz-form [formGroup]="qrcodeForm">
<nz-form-item class="nz-form-item">
<nz-form-label class="nz-formlable" nzFor="type" nzRequired>二维码用途</nz-form-label>
<nz-form-control>
<nz-radio-group name="type" [nzDisabled]="id" formControlName="type" (ngModelChange)="qrcodeTypeChange($event)">
<label nz-radio nzValue="1">扫码后关注公众号</label>
<label nz-radio nzValue="2">扫码后参与指定活动</label>
</nz-radio-group>
</nz-form-control>
</nz-form-item>
<nz-form-item class="nz-form-item">
<nz-form-label class="nz-formlable" nzFor="fissionId" nzRequired>模板活动</nz-form-label>
<nz-form-control>
<nz-select name="fissionId" [nzDisabled]="id" formControlName="fissionId" nzAllowClear
style="width: 260px;" nzPlaceHolder="请选择模板活动">
<nz-option *ngFor="let opt of fissionList" nzValue="{{ opt.id }}" nzLabel="{{ opt.name }}">
</nz-option>
</nz-select>
<nz-form-explain *ngIf="qrcodeForm.get('fissionId')?.dirty && qrcodeForm.get('fissionId')?.errors">
请选择模板活动!
</nz-form-explain>
</nz-form-control>
</nz-form-item>
</form>
```
## 表单初始化
注意点：
如果控件初始值为空，输入框input的值要设为''，其他控件的值都要设为null，否则可能会有placeholder不显示的问题
这里写的控件名要一一与html上的formControlName对应
控件可以添加自己写的验证规则
```ts
import { FormBuilder, Validators, FormGroup } from '@angular/forms';
// qrcodeForm: FormGroup;
// fb: FormBuilder
this.qrcodeForm = this.fb.group({
type: ["1", [Validators.required]], // 二维码用途
action: ["2", [Validators.required]], // 二维码类型
name: ['', [Validators.required, this.qrcodeNameValidator]], // 二维码名称
fissionId: [null], // 模板活动
weixinMpId: [null, [Validators.required]], // 公众号
expireDays: ['', [Validators.required, this.expireDaysValidator]], // 有效天数
sourceId: [null, [Validators.required]], // 来源
sourceContent: ['', [this.sourceContentValidator]],
replyContent: ['']
});
```
## 表单取值
```ts
// 取表单里的单个值
let name = this.qrcodeForm.controls.name.value;
// 取表单里的所有值
let data = this.qrcodeForm.getRawValue();
表单赋值
patchValue的参数可以是多个，也可以是单个，通常都用patchValue赋值
setValue的参数必须为表单里所有的控件值，且如果赋的值验证不通过会提示错误信息
// patchValue
this.qrcodeForm.patchValue({
type: res.type.toString(), // 二维码用途
action: res.action.toString(), // 二维码类型
name: res.name, // 二维码名称
fissionId: res.fissionId ? res.fissionId.toString() : null, // 模板活动
weixinMpId: res.weixinMpId.toString(), // 公众号
});
// setValue
this.qrcodeForm.setValue({
type: res.type.toString(), // 二维码用途
action: res.action.toString(), // 二维码类型
name: res.name, // 二维码名称
fissionId: res.fissionId ? res.fissionId.toString() : null, // 模板活动
weixinMpId: res.weixinMpId.toString(), // 公众号
expireDays: res.expireDays ? res.expireDays.toString() : '1', // 有效天数
sourceId: res.sourceId.toString(), // 来源
sourceContent: res.sourceContent, // 来源内容
replyContent: res.replyContent
});
```
## 表单增加和删除控件项
```ts
// 增加控件项
this.qrcodeForm.addControl('point', this.fb.control(null, Validators.required));
// 删除控件项
this.qrcodeForm.removeControl('point');
表单动态增加和删除验证
页面有时候在选中一个下拉框选项时，需要隐藏或显示另外一个控件，这个控件需要把验证加上或删除，否则页面虽然看不到这个控件了，但提交表单仍可能通不过验证
clearValidators后，要调用updateValueAndValidity重新计算控件值并更新验证状态
// 增加验证
this.qrcodeForm.controls.fissionId.setValidators(Validators.required);
// 删除验证
this.qrcodeForm.controls.fissionId.clearValidators();
this.qrcodeForm.controls.fissionId.updateValueAndValidity();
提交表单
提交表单需要先在前端进行验证，需要调用public-method里的表单验证方法，校验不通过时，不用去请求接口
通过判断this.qrcodeForm.valid可以知道验证状态，true为校验通过，false为校验不通过
import { FormMethod } from '../../../common/public-method';
// 表单部分的通用方法
export const FormMethod = {
/**
* 更新表单状态
* @param form FormGroup
*/
updateFormStatus: (form: FormGroup): void => {
// tslint:disable-next-line:forin
for (const i in form.controls) {
form.controls[i].markAsDirty();
form.controls[i].updateValueAndValidity();
}
}
};
```
// 验证每个组件，如果有错误会显示信息
FormMethod.updateFormStatus(this.qrcodeForm);
// 校验不通过，返回
if (!this.qrcodeForm.valid) {
return;
}
```
TS:
```ts
import { FormBuilder } from '@angular/forms';
export class CartComponent implements OnInit {
checkoutForm:any;
constructor(
private formBuilder: FormBuilder
) {
this.checkoutForm = this.formBuilder.group({
name: '',
address: ''
});
}
onSubmit(formData:object){
//获取到要提交的表单的数据
console.log('form data: ',formData);
//购物车数据提交后需要清空
this.cart=this.cartService.clearCart();
//表单重置
this.checkoutForm.reset()
}
}
```
HTML:
```html
<form class="form" [formGroup]="checkoutForm" (ngSubmit)="onSubmit(checkoutForm.value)">
<div class="form_cow">
<label>Name</label>
<input type="text" formControlName="name">
</div>
<div class="form_cow">
<label>Address</label>
<input type="text" formControlName="address">
</div>
<button class="button" nz-button nzType="primary" type="submit">submit</button>
</form>
```
### 防抖
```ts
import { Observable, of, } from 'rxjs';
import { catchError, map, tap ,switchMap,distinctUntilChanged,debounceTime,combineLatest} from 'rxjs/operators';
private searchText$ = new Subject<string>();
search(packageName: string) {
this.searchText$.next(packageName);
}
ngOnInit() {
this.packages$ = this.searchText$.pipe(
debounceTime(500),
distinctUntilChanged(),
switchMap(packageName =>
this.searchService.search(packageName))
);
}
constructor(private searchService: PackageSearchService) { }
```
## http
app.module；
```ts
import {HttpClientModule,HttpClientJsonpModule } from "@angular/common/http";
```
使用的模块引入，一般为某个service:
```ts
import { HttpClient, HttpParams,HttpHeaders } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { catchError, map, tap ,filter} from 'rxjs/operators';
constructor(
private http:HttpClient
) { }
//get获取数据
public get(path:string,params:any){
let url=environment.baseUrl+path;
let dataParams = new HttpParams();
for (const key in params) {
if (params[key] === false || params[key]) {
dataParams = dataParams.set(key, params[key]);
}
}
// 底层http调用
return this.http.get(url, { params: dataParams })
// 响应转化为Promise
// .toPromise();
}
//post发送请求
public post(path:string,option:any){
const httpOptions = {
headers: new HttpHeaders({
'Content-Type': 'application/json',
'Authorization': 'my-auth-token'
})
}
return this.http.post<Hero>(path, data, httpOptions)
}
//请求头是不能修改的，只能重置
httpOptions.headers = httpOptions.headers.set('Authorization', 'my-new-auth-token');
```
返回的数据都是一个Observable对象，使用subscribe()来获取
调用该服务;
```ts
//请求json数据时
this.service.post(path,parma).subscribe(
(data: Config) => this.config = { ...data }, // success path
error => this.error = error // error path
)
//请求非json数据时
this.service.post(path,parma).pipe(
tap(
data => this.log(filename, data),
error => this.logError(filename, error)
);
).subscribe()
```
## RXJS
ReactiveX来自微软，它是一种针对异步数据流的编程
```ts
const ob = Observable.fromPromise(somePromise); // Promise转为Observable
const promise = someObservable.toPromise(); // Observable转为Promise
```
优点：
- 一次可发送多个请求
- 可以取消订阅
### Observable 用法
```ts
import {Observable} from 'rxjs'
function xxx(){
return new Observable((observable)=>{
this.httpService.get('/blog',{},false).then(((res:Respones)=>{
if(res.code===200){
observable.next(res)
}else if(res.status==='ok'){
observable.next(res)
}else{
observable.error(res)
}
}))
})
}
//调用
xxx().pipe(
filter((res)=>{
return res.code>0
}
)
//map
xxx().pipe(
map((res)=>{
return res.data
}
)
).subscribe((res)=>{
console.log(res);
//这里被订阅了才会执行
})
```
### 使用 RXJS防抖
```js
var text = document.querySelector('#text');
var inputStream = Rx.Observable.fromEvent(text, 'keyup') //为dom元素绑定'keyup'事件
.debounceTime(250) // 防抖动
.pluck('target', 'value') // 取值
.switchMap(url => Http.get(url)) // 将当前输入流替换为http请求
.subscribe(data => render(data)); // 接收数据
```
# 总结以及要注意地方
### 父子组件的传值
父组件
```ts
import { Component, OnInit ,ViewChild} from '@angular/core';
@ViewChild('demo') son:any;
console.log("son:",this.son.str);
```
子组件
```ts
import { Component, OnInit ,ViewChild,Input,Output,EventEmitter} from '@angular/core';
public str:string="song daat00000"
@Input () parentData:any;
@Input() fromFun:any;
@Output() testSon=new EventEmitter();
console.log(this.parentData);
ngAfterViewInit() {
//在这个钩子中来操作DOM
console.log('demo view load');
let demo:any=document.getElementById('demo')
//console.log(demo);
console.log(this.myDemo.nativeElement.innerHTML);
}
//方法
test(){
this.testSon.emit('son emit')
}
```
### 渲染
获取数据之前页面会渲染一次，直接渲染未定义的数据会报错，所以渲染数据之前要用*ngIf先进行判断；
组件间通信
组件之间的交互方式，通常有以下几种：
1 通过输入型绑定把数据从父组件传到子组件
```ts
@Input()
子组件：
import { Component, Input } from '@angular/core';
import { Hero } from './hero';
@Component({
selector: 'app-hero-child',
template: `
<h3>{{hero.name}} says:</h3>
<p>I, {{hero.name}}, am at your service, {{masterName}}.</p>
`
})
export class HeroChildComponent {
@Input() hero: Hero;
@Input('master') masterName: string;
}
父组件：
import { Component } from '@angular/core';
import { HEROES } from './hero';
@Component({
selector: 'app-hero-parent',
template: `
<h2>{{master}} controls {{heroes.length}} heroes</h2>
<app-hero-child *ngFor="let hero of heroes"
[hero]="hero"
[master]="master">
</app-hero-child>
`
})
export class HeroParentComponent {
heroes = HEROES;
master = 'Master';
}
```
## 2 通过ngOnChanges()来截听输入属性值的变化
使用 OnChanges 生命周期钩子接口的 ngOnChanges() 方法来监测输入属性值的变化并做出回应。
子组件：
```ts
import { Component, Input, OnChanges, SimpleChange } from '@angular/core';
@Component({
selector: 'app-version-child',
template: `
<h3>Version {{major}}.{{minor}}</h3>
<h4>Change log:</h4>
<ul>
<li *ngFor="let change of changeLog">{{change}}</li>
</ul>
`
})
export class VersionChildComponent implements OnChanges {
@Input() major: number;
@Input() minor: number;
changeLog: string[] = [];
ngOnChanges(changes: {[propKey: string]: SimpleChange}) {
let log: string[] = [];
for (let propName in changes) {
let changedProp = changes[propName];
let to = JSON.stringify(changedProp.currentValue);
if (changedProp.isFirstChange()) {
log.push(`Initial value of ${propName} set to ${to}`);
} else {
let from = JSON.stringify(changedProp.previousValue);
log.push(`${propName} changed from ${from} to ${to}`);
}
}
this.changeLog.push(log.join(', '));
}
}
```
父组件:
```ts
import { Component } from '@angular/core';
@Component({
selector: 'app-version-parent',
template: `
<h2>Source code version</h2>
<button (click)="newMinor()">New minor version</button>
<button (click)="newMajor()">New major version</button>
<app-version-child [major]="major" [minor]="minor"></app-version-child>
`
})
export class VersionParentComponent {
major = 1;
minor = 23;
newMinor() {
this.minor++;
}
newMajor() {
this.major++;
this.minor = 0;
}
}
```
3 EventEmitter弹射事件
父组件监听子组件的事件,子组件暴露一个 EventEmitter 属性，当事件发生时，子组件利用该属性 emits(向上弹射)事件。父组件绑定到这个事件属性，并在事件发生时作出回应。子组件的 EventEmitter 属性是一个输出属性，通常带有@Output 装饰器，就像在 VoterComponent 中看到的。
子组件：
import { Component, EventEmitter, Input, Output } from '@angular/core';
@Component({
selector: 'app-voter',
template: `
<h4>{{name}}</h4>
<button (click)="vote(true)" [disabled]="didVote">Agree</button>
<button (click)="vote(false)" [disabled]="didVote">Disagree</button>
`
})
export class VoterComponent {
@Input() name: string;
@Output() voted = new EventEmitter<boolean>();
didVote = false;
vote(agreed: boolean) {
this.voted.emit(agreed);
this.didVote = true;
}
}
父组件：
import { Component } from '@angular/core';
@Component({
selector: 'app-vote-taker',
template: `
<h2>Should mankind colonize the Universe?</h2>
<h3>Agree: {{agreed}}, Disagree: {{disagreed}}</h3>
<app-voter *ngFor="let voter of voters"
[name]="voter"
(voted)="onVoted($event)">
</app-voter>
`
})
export class VoteTakerComponent {
agreed = 0;
disagreed = 0;
voters = ['Mr. IQ', 'Ms. Universe', 'Bombasto'];
onVoted(agreed: boolean) {
agreed ? this.agreed++ : this.disagreed++;
}
}
4 ViewChild
父组件调用@ViewChild()，如果父组件的类需要读取子组件的属性值或调用子组件的方法，可以把子组件作为 ViewChild，注入到父组件里面。
子组件：
import { Component, OnDestroy, OnInit } from '@angular/core';
@Component({
selector: 'app-countdown-timer',
template: '<p>{{message}}</p>'
})
export class CountdownTimerComponent implements OnInit, OnDestroy {
intervalId = 0;
message = '';
seconds = 11;
clearTimer() { clearInterval(this.intervalId); }
ngOnInit() { this.start(); }
ngOnDestroy() { this.clearTimer(); }
start() { this.countDown(); }
stop() {
this.clearTimer();
this.message = `Holding at T-${this.seconds} seconds`;
}
private countDown() {
this.clearTimer();
this.intervalId = window.setInterval(() => {
this.seconds -= 1;
if (this.seconds === 0) {
this.message = 'Blast off!';
} else {
if (this.seconds < 0) { this.seconds = 10; } // reset
this.message = `T-${this.seconds} seconds and counting`;
}
}, 1000);
}
}
父组件：
import { AfterViewInit, ViewChild } from '@angular/core';
import { Component } from '@angular/core';
import { CountdownTimerComponent } from './countdown-timer.component';
@Component({
selector: 'app-countdown-parent-vc',
template: `
<h3>Countdown to Liftoff (via ViewChild)</h3>
<button (click)="start()">Start</button>
<button (click)="stop()">Stop</button>
<div class="seconds">{{ seconds() }}</div>
<app-countdown-timer></app-countdown-timer>
`,
styleUrls: ['../assets/demo.css']
})
export class CountdownViewChildParentComponent implements AfterViewInit {
@ViewChild(CountdownTimerComponent)
private timerComponent: CountdownTimerComponent;
seconds() { return 0; }
ngAfterViewInit() {
// Redefine `seconds()` to get from the `CountdownTimerComponent.seconds` ...
// but wait a tick first to avoid one-time devMode
// unidirectional-data-flow-violation error
setTimeout(() => this.seconds = () => this.timerComponent.seconds, 0);
}
start() { this.timerComponent.start(); }
stop() { this.timerComponent.stop(); }
}
5 RxJS的Observable
父组件和子组件通过服务来通讯，父组件和它的子组件共享同一个服务，利用该服务在组件家族内部实现双向通讯。
该服务实例的作用域被限制在父组件和其子组件内。这个组件子树之外的组件将无法访问该服务或者与它们通讯。
服务：
import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';
@Injectable()
export class MissionService {
// Observable string sources
private missionAnnouncedSource = new Subject<string>();
private missionConfirmedSource = new Subject<string>();
// Observable string streams
missionAnnounced$ = this.missionAnnouncedSource.asObservable();
missionConfirmed$ = this.missionConfirmedSource.asObservable();
// 父组件调用子组件
announceMission(mission: string) {
this.missionAnnouncedSource.next(mission);
}
//子组件调用父组件
confirmMission(astronaut: string) {
this.missionConfirmedSource.next(astronaut);
}
}
子组件：
import { Component, Input, OnDestroy } from '@angular/core';
import { MissionService } from './mission.service';
import { Subscription } from 'rxjs';
@Component({
selector: 'app-astronaut',
template: `
<p>
{{astronaut}}: <strong>{{mission}}</strong>
<button
(click)="confirm()"
[disabled]="!announced || confirmed">
Confirm
</button>
</p>
`
})
export class AstronautComponent implements OnDestroy {
@Input() astronaut: string;
mission = '<no mission announced>';
confirmed = false;
announced = false;
subscription: Subscription;
constructor(private missionService: MissionService) {
this.subscription = missionService.missionAnnounced$.subscribe(
mission => {
this.mission = mission;
this.announced = true;
this.confirmed = false;
});
}
confirm() {
this.confirmed = true;
this.missionService.confirmMission(this.astronaut);
}
ngOnDestroy() {
// prevent memory leak when component destroyed
this.subscription.unsubscribe();
}
}
父组件：
import { Component } from '@angular/core';
import { MissionService } from './mission.service';
@Component({
selector: 'app-mission-control',
template: `
<h2>Mission Control</h2>
<button (click)="announce()">Announce mission</button>
<app-astronaut *ngFor="let astronaut of astronauts"
[astronaut]="astronaut">
</app-astronaut>
<h3>History</h3>
<ul>
<li *ngFor="let event of history">{{event}}</li>
</ul>
`,
providers: [MissionService]
})
export class MissionControlComponent {
astronauts = ['Lovell', 'Swigert', 'Haise'];
history: string[] = [];
missions = ['Fly to the moon!',
'Fly to mars!',
'Fly to Vegas!'];
nextMission = 0;
constructor(private missionService: MissionService) {
missionService.missionConfirmed$.subscribe(
astronaut => {
this.history.push(`${astronaut} confirmed the mission`);
});
}
announce() {
let mission = this.missions[this.nextMission++];
this.missionService.announceMission(mission);
this.history.push(`Mission "${mission}" announced`);
if (this.nextMission >= this.missions.length) { this.nextMission = 0; }
}
}