Angular 4 组件中的 HttpClient 无法解析所有参数
Angular 4 HttpClient in Component Can't resolve all parameters
我开始学习 Angular 4 并学习了 HTTP 客户端部分。现在我正在尝试从组件进行 http 调用(是的,我知道我应该将它转移到服务,但仍然)
但出于某种原因,当我尝试将 HttpClient 注入我的组件时,出现了下一个错误:
Uncaught Error: Can't resolve all parameters for PromocodeComponent:
(?).
这是我的组件的代码:
import { Ticket } from '../../classes/Ticket.class'
import { Component, Input } from '@angular/core';
import { HttpClient } from '@angular/common/http';
@Component({
selector: 'promocode',
templateUrl: './promocode.template.html',
styleUrls: ['./promocode.styles.scss']
})
export class PromocodeComponent {
@Input() ticket: Ticket;
state: String = "normal";
promocode: String = "";
constructor(private http: HttpClient) {}
promocodeValidate(event): void{
console.log(this.promocode);
console.log(event);
this.http.get('/promocode/asdasda').subscribe(data => {
console.log(data);
});
}
}
还有我的app.module.ts:
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
import { MovieBadgeComponent } from './movie-badge/movie-badge.component';
import { TicketComponent } from './ticket/ticket.component';
import { PromocodeComponent} from './promocode/promocode.component';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
@NgModule({
declarations: [
AppComponent,
MovieBadgeComponent,
TicketComponent,
PromocodeComponent
],
imports: [
BrowserModule,
HttpClientModule,
FormsModule
],
providers: [],
bootstrap: [ AppComponent ]
})
export class AppModule {}
结果,我错过了
"emitDecoratorMetadata": true
在 tsconfig
fml...
事实证明,对我来说,我忘记了服务中的 @Injectable
装饰器。在之前的 angular (>=2) 中,我记得 @Injectable
是可选的……猜猜是不是?
当我使用 Angular 运行 单元测试(spec.ts 文件)时,我遇到了同样的错误。
以下是我做的:
import { HttpClientModule, HttpClient } from '@angular/common/http';
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [ ],
imports: [
HttpClientModule
],
schemas: [NO_ERRORS_SCHEMA],
providers: [
HttpClient,
]
})
.compileComponents();
}));
错误消失了。
我开始学习 Angular 4 并学习了 HTTP 客户端部分。现在我正在尝试从组件进行 http 调用(是的,我知道我应该将它转移到服务,但仍然)
但出于某种原因,当我尝试将 HttpClient 注入我的组件时,出现了下一个错误:
Uncaught Error: Can't resolve all parameters for PromocodeComponent: (?).
这是我的组件的代码:
import { Ticket } from '../../classes/Ticket.class'
import { Component, Input } from '@angular/core';
import { HttpClient } from '@angular/common/http';
@Component({
selector: 'promocode',
templateUrl: './promocode.template.html',
styleUrls: ['./promocode.styles.scss']
})
export class PromocodeComponent {
@Input() ticket: Ticket;
state: String = "normal";
promocode: String = "";
constructor(private http: HttpClient) {}
promocodeValidate(event): void{
console.log(this.promocode);
console.log(event);
this.http.get('/promocode/asdasda').subscribe(data => {
console.log(data);
});
}
}
还有我的app.module.ts:
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { AppComponent } from './app.component';
import { MovieBadgeComponent } from './movie-badge/movie-badge.component';
import { TicketComponent } from './ticket/ticket.component';
import { PromocodeComponent} from './promocode/promocode.component';
import { FormsModule } from '@angular/forms';
import { HttpClientModule } from '@angular/common/http';
@NgModule({
declarations: [
AppComponent,
MovieBadgeComponent,
TicketComponent,
PromocodeComponent
],
imports: [
BrowserModule,
HttpClientModule,
FormsModule
],
providers: [],
bootstrap: [ AppComponent ]
})
export class AppModule {}
结果,我错过了
"emitDecoratorMetadata": true
在 tsconfig
fml...
事实证明,对我来说,我忘记了服务中的 @Injectable
装饰器。在之前的 angular (>=2) 中,我记得 @Injectable
是可选的……猜猜是不是?
当我使用 Angular 运行 单元测试(spec.ts 文件)时,我遇到了同样的错误。
以下是我做的:
import { HttpClientModule, HttpClient } from '@angular/common/http';
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [ ],
imports: [
HttpClientModule
],
schemas: [NO_ERRORS_SCHEMA],
providers: [
HttpClient,
]
})
.compileComponents();
}));
错误消失了。