Angular NGRX TypeError:操作必须具有类型属性

我不明白如何避免这样的错误

NGRX-TypeError：操作必须有一个type属性

。请帮我找出哪里出了问题

我有两个动作，

export class UpdateWordListAction implements Action {
    static readonly TYPE: 'UPDATE_WORD_LIST';
    readonly type: "UPDATE_WORD_LIST";
    constructor() {};
}
export class WordListLoadedSuccessAction implements Action {
    readonly words: Word[];
    static readonly TYPE: 'WORD_LIST_LOADED_SUCCESS';
    readonly type: "WORD_LIST_LOADED_SUCCESS";
    constructor(words: Word[]) {};
}

@Injectable()
export class MyEffects {
 
     testEffect$ = createEffect(() => 
      this.actions$.pipe(
        ofType(UpdateWordListAction.TYPE),
        switchMap(() => this.wordService.getWordList()),
        map(words => new WordListLoadedSuccessAction(words)),
        catchError(() => EMPTY)));
 
  constructor(
    private actions$: Actions,
    private wordService: WordService
  ) {}
}

一种效果，

export class UpdateWordListAction implements Action {
    static readonly TYPE: 'UPDATE_WORD_LIST';
    readonly type: "UPDATE_WORD_LIST";
    constructor() {};
}
export class WordListLoadedSuccessAction implements Action {
    readonly words: Word[];
    static readonly TYPE: 'WORD_LIST_LOADED_SUCCESS';
    readonly type: "WORD_LIST_LOADED_SUCCESS";
    constructor(words: Word[]) {};
}

@Injectable()
export class MyEffects {
 
     testEffect$ = createEffect(() => 
      this.actions$.pipe(
        ofType(UpdateWordListAction.TYPE),
        switchMap(() => this.wordService.getWordList()),
        map(words => new WordListLoadedSuccessAction(words)),
        catchError(() => EMPTY)));
 
  constructor(
    private actions$: Actions,
    private wordService: WordService
  ) {}
}

以及此类客户

this.store.dispatch(new UpdateWordListAction());

---

您需要使用赋值符号而不是冒号。试试这个：

    export class UpdateWordListAction implements Action {
       readonly type = "UPDATE_WORD_LIST";
       constructor() {};
    }