我无法在 Angular 中使用 Output 和 EventEmitter 在应用程序组件中获取 component(post) 的 属性
I cannot get the a property of component(post) in the app component using Output and EventEmitter in Angular
它说 any 类型的参数不可赋值。
我应该在 app.component 中导入其他内容吗?
你能告诉我我做错了什么吗?
app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'test';
posts=[];
onAddedPost(post){
this.posts.push(post)
}
}
问题来了。 onAddedPost 中的 post 是问题所在。
post-create.component.ts
import { sharedStylesheetJitUrl } from '@angular/compiler';
import { Component, EventEmitter, Injectable, Output, OutputDecorator } from '@angular/core';
@Component({
selector: 'app-post-create',
templateUrl: './post-create.component.html',
styleUrls: ['./post-create.component.css']
})
export class PostCreateComponent {
enteredContent='';
enteredTitle='';
@Output() postCreated = new EventEmitter();
onAddPost(){
const post={title:this.enteredTitle,content:this.enteredContent};
this.postCreated.emit(post);
}
}
app.component.html
<app-header></app-header>
<main>
<app-post-create (postCreated)="onPostAdded($event)" ></app-post-create>
<app-post-list [posts]="storedPosts"></app-post-list>
</main>
app.module.ts
@NgModule({
declarations: [
AppComponent,
PostCreateComponent,
HeaderComponent,
PostListComponent
],
imports: [
BrowserModule,
AppRoutingModule,
FormsModule,
BrowserAnimationsModule,
MatInputModule,
MatCardModule,
MatButtonModule,
MatToolbarModule,
MatExpansionModule,
],
bootstrap: [AppComponent]
})
export class AppModule { }
或许您可以创建一个 class Post 并将其用于您的 EventEmitter。
export class Post {
title: string;
content: string;
}
@Output() postCreated = new EventEmitter<Post>();
很可能是 TSLint 错误,因为它无法推断类型。注意:这不会影响应用程序,因为编译后的 JS 无法识别 TS 类型。
但是要解决它,您可以定义一个类型的 Typescript 接口。
- 定义模型
post.ts
export interface Post {
title?: string;
content?: string;
}
- 使用此模型在两个组件中定义类型。
post-create.component.ts
import { sharedStylesheetJitUrl } from '@angular/compiler';
import { Component, EventEmitter, Injectable, Output, OutputDecorator } from '@angular/core';
import { Post } from './post';
@Component({
selector: 'app-post-create',
templateUrl: './post-create.component.html',
styleUrls: ['./post-create.component.css']
})
export class PostCreateComponent {
enteredContent='';
enteredTitle='';
@Output() postCreated: EventEmitter<Post> = new EventEmitter<Post>();
onAddPost(){
const post: Post = {
title: this.enteredTitle,
content: this.enteredContent
};
this.postCreated.emit(post);
}
}
app.component.ts
import { Component } from '@angular/core';
import { Post } from './post';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'test';
posts: Post[] = [];
onAddedPost(post: Post) {
this.posts.push(post);
}
}
它说 any 类型的参数不可赋值。
我应该在 app.component 中导入其他内容吗?
你能告诉我我做错了什么吗?
app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'test';
posts=[];
onAddedPost(post){
this.posts.push(post)
}
}
问题来了。 onAddedPost 中的 post 是问题所在。 post-create.component.ts
import { sharedStylesheetJitUrl } from '@angular/compiler';
import { Component, EventEmitter, Injectable, Output, OutputDecorator } from '@angular/core';
@Component({
selector: 'app-post-create',
templateUrl: './post-create.component.html',
styleUrls: ['./post-create.component.css']
})
export class PostCreateComponent {
enteredContent='';
enteredTitle='';
@Output() postCreated = new EventEmitter();
onAddPost(){
const post={title:this.enteredTitle,content:this.enteredContent};
this.postCreated.emit(post);
}
}
app.component.html
<app-header></app-header>
<main>
<app-post-create (postCreated)="onPostAdded($event)" ></app-post-create>
<app-post-list [posts]="storedPosts"></app-post-list>
</main>
app.module.ts
@NgModule({
declarations: [
AppComponent,
PostCreateComponent,
HeaderComponent,
PostListComponent
],
imports: [
BrowserModule,
AppRoutingModule,
FormsModule,
BrowserAnimationsModule,
MatInputModule,
MatCardModule,
MatButtonModule,
MatToolbarModule,
MatExpansionModule,
],
bootstrap: [AppComponent]
})
export class AppModule { }
或许您可以创建一个 class Post 并将其用于您的 EventEmitter。
export class Post {
title: string;
content: string;
}
@Output() postCreated = new EventEmitter<Post>();
很可能是 TSLint 错误,因为它无法推断类型。注意:这不会影响应用程序,因为编译后的 JS 无法识别 TS 类型。
但是要解决它,您可以定义一个类型的 Typescript 接口。
- 定义模型
post.ts
export interface Post {
title?: string;
content?: string;
}
- 使用此模型在两个组件中定义类型。
post-create.component.ts
import { sharedStylesheetJitUrl } from '@angular/compiler';
import { Component, EventEmitter, Injectable, Output, OutputDecorator } from '@angular/core';
import { Post } from './post';
@Component({
selector: 'app-post-create',
templateUrl: './post-create.component.html',
styleUrls: ['./post-create.component.css']
})
export class PostCreateComponent {
enteredContent='';
enteredTitle='';
@Output() postCreated: EventEmitter<Post> = new EventEmitter<Post>();
onAddPost(){
const post: Post = {
title: this.enteredTitle,
content: this.enteredContent
};
this.postCreated.emit(post);
}
}
app.component.ts
import { Component } from '@angular/core';
import { Post } from './post';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'test';
posts: Post[] = [];
onAddedPost(post: Post) {
this.posts.push(post);
}
}