这可能是由于在dispatch前未注入Effect源或在提供程序中未正确声明导致的。以下是一个示例:
在您的模块中引入Effects和Store模块:
import { EffectsModule } from '@ngrx/effects'; import { StoreModule } from '@ngrx/store';
@NgModule({ imports: [ StoreModule.forRoot({}), EffectsModule.forRoot([]), ... ], ... })
在您的组件或服务文件中,创建一个action并使用dispatch将其发送到store:
import { MyAction } from '../store/my-action.actions'; import { Store } from '@ngrx/store';
constructor(private store: Store) {}
triggerAction() { this.store.dispatch(new MyAction()); }
在您的Effect中,监听您的Action并执行所需的操作:
import { Injectable } from '@angular/core'; import { Actions, Effect, ofType } from '@ngrx/effects'; import { MyAction } from '../store/my-action.actions'; import { tap } from 'rxjs/operators';
@Injectable() export class MyEffect { @Effect({dispatch: false}) myAction$ = this.actions$.pipe( ofType(MyAction), tap(() => console.log('MyAction was dispatched!')) );
constructor(private actions$: Actions) {}
}
确认在提供程序中正确声明effect:
import { EffectsModule } from '@ngrx/effects'; import { MyEffect } from './my-effect.effects';
@NgModule({ imports: [ ... EffectsModule.forFeature([MyEffect]), ... ], declarations: [...], providers: [ MyEffect, ... ] })
这些步骤应该能够使Effects在dispatch操作时被正确调用。