现在创建了一个简单的组件，但出现有关提供程序的错误

如何解决现在创建了一个简单的组件，但出现有关提供程序的错误

做这个项目，我创建了一个简单的组件来放置我的广告，现在我遇到了这个错误，我无法解决：

StaticInjectorError（AppModule）[discountAllertComponent]： StaticInjectorError（平台：核心）[discountAllertComponent]： NullInjectorError：discountAllertComponent的提供者！

我像往常一样创建了该组件，但我不知道该怎么做才能修复它！

组件：

import { Component,OnInit } from '@angular/core';
import {AngularFireDatabase} from '@angular/fire/database';
import {AlertController} from '@ionic/angular';
import {Router} from '@angular/router';

@Component({
  selector: 'app-discount-allert',templateUrl: './discount-allert.component.html',styleUrls: ['./discount-allert.component.scss'],})
export class discountAllertComponent implements OnInit {

  constructor(
      // public af: AngularFireDatabase,public alertController: AlertController) { }

  ngOnInit() {}
}

组件模块：

mport {CUSTOM_ELEMENTS_SCHEMA,NgModule} from '@angular/core';
import {CommonModule} from '@angular/common';
import {SharedHeaderComponent} from './shared-header/shared-header.component';
import {AlertController,IonicModule} from '@ionic/angular';
import {UserInfoComponent} from './user-info/user-info.component';
import {AddressComponent} from './address/address.component';
import {FormsModule,ReactiveFormsModule} from '@angular/forms';
import {TranslateModule} from '@ngx-translate/core';
import {PasswordStrengthBarModule} from 'ng2-password-strength-bar';
import {SchedulerComponent} from './scheduler/scheduler.component';
import {OrderConfigurationComponent} from './order-configuration/order-configuration.component';
import {OrderComponent} from './order/order.component';
import {MenuComponent} from './menu/menu.component';
import {dishOptionsComponent} from './dish-options/dish-options.component';
import {PasswordResetComponent} from './password-reset/password-reset.component';
import {OrderResumeComponent} from './order-resume/order-resume.component';
import {PaymentMethodComponent} from './payment-method/payment-method.component';
import {OnlinePaymentComponent} from './online-payment/online-payment.component';
import {PipesModule} from '../pipes/pipes.module';
import {ChangePasswordComponent} from './change-password/change-password.component';
import {CardsManagerComponent} from './cards-manager/cards-manager.component';
import {LocationSelectComponent} from './location-select/location-select.component';
import {MbrefComponent} from './mbref/mbref.component';
import {MbwayComponent} from './mbway/mbway.component';
import {CardModule} from '../directives/card/module';
import {discountAllertComponent} from './discount-allert/discount-allert.component';

const COMPONENTS = [
  AddressComponent,CardsManagerComponent,ChangePasswordComponent,dishOptionsComponent,LocationSelectComponent,MbrefComponent,MbwayComponent,MenuComponent,OrderComponent,OrderConfigurationComponent,OrderResumeComponent,PasswordResetComponent,SchedulerComponent,SharedHeaderComponent,UserInfoComponent,PaymentMethodComponent,OnlinePaymentComponent,discountAllertComponent
];

@NgModule({
  declarations: [COMPONENTS],imports: [
    IonicModule,CardModule,CommonModule,FormsModule,PasswordStrengthBarModule,ReactiveFormsModule,TranslateModule,PipesModule,],schemas: [CUSTOM_ELEMENTS_SCHEMA],exports: [COMPONENTS],entryComponents: [COMPONENTS],})
export class ComponentsModule {
}

解决方法

为页面创建组件时，必须在正在使用的页面的声明中的.module.ts文件中声明它：[]。例如

declarations: [DiscountAllertComponent]

如果仍然无法使用，请尝试将其添加到：

  entryComponents: [DiscountAllertComponent]