import { NgModule }    from '@angular/core';
import { RouterModule, Routes } from '@angular/router';

import { DetailResolver }  from './detail-resolver.service';
import { DetailComponent }  from './detail.component';

const routes: Routes = [
 {
 path: ':id',
 component: DetailComponent,
 resolve: { // 此处使用resolve
  detail: DetailResolver
 }
 },
];
@NgModule({
 imports: [
 RouterModule.forChild(routes)
 ],
 exports: [
 RouterModule
 ],
 providers: [
 DetailResolver
 ]
})
export class HomeRoutingModule { }

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

import { detail, DetailService } from './detail.service';

@Injectable()
export class DetailResolver implements Resolve<Detail> {
 constructor(private detailService: DetailService, private router: Router) {}

 resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Detail> {
 let id = route.paramMap.get('id');

 return this.detailService.getDetail(id).pipe(
  take(1), // 可选，只发出源 Observable 最初发出的的1个值
  map(res => {
  if (res) {
   return res;
  } else { // 请求失败时拦截跳转
   this.router.navigate(['/home']);
   return null;
  }
  })
 );
 }
}

// 通过 route 获取 detail-resolver.service 中 detailService.getDetail 请求的数据
ngOnInit() {
 this.route.data
 .subscribe((data: { detail: Detail }) => {
  this.detail = data.detail; 
 });
}