角度解析程序不工作没有()的提供程序

我在一个新项目中遇到了这个问题。

const routes: Routes = [
    {
        path: '',
        component: CategoriesComponent,
    },
    {
        path: ':categoryId',
        component: CategoryComponent,
        resolve: CategoryResolver,
    },
];

如您所见,它正在尝试使用解析程序,如下所示:

import { Injectable } from '@angular/core';
import { ActivatedRouteSnapshot, Resolve, RouterStateSnapshot } from '@angular/router';
import { Observable } from 'rxjs';

import { Category, CategoryService } from '@situlive/angular/data';

@Injectable({
    providedIn: 'root',
})
export class CategoryResolver implements Resolve<Category> {
    constructor(private categoryService: CategoryService) {}

    resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Category> {
        return this.categoryService.get(route.paramMap.get('categoryId'));
    }
}

当我使用此代码时,我得到一个错误:

NullInjectorError:没有()的提供程序=>[!

如果我这样注释解析程序:

const routes: Routes = [
    {
        path: '',
        component: CategoriesComponent,
    },
    {
        path: ':categoryId',
        component: CategoryComponent,
        //resolve: CategoryResolver,
        children: [
            {
                path: 'criteria',
                loadChildren: () => import('../criteria/criteria.module').then((m) => m.CriteriaModule),
            },
            {
                path: 'feeds',
                loadChildren: () => import('../feeds/feeds.module').then((m) => m.FeedsModule),
            },
            {
                path: 'fields',
                loadChildren: () => import('../fields/fields.module').then((m) => m.FieldsModule),
            },
        ],
    },
];

我不再得到错误,但显然没有解决任何问题。 我的代码在我的 类别成分 就像这样:

ngOnInit(): void {
    this.getCategory();
}

private getCategory(): void {
    this.category = this.route.snapshot.data.category;
}

有人知道为什么会这样吗?