mode_edit codeAPI / @angular/routerPreloadingStrategylinkclass 试验性的Provides a preloading strategy.abstract class PreloadingStrategy { abstract preload(route: Route, fn: () => Observable<any>): Observable<any> }子类link NoPreloading PreloadAllModules 方法linkpreload() linkmode_edit codeabstract preload(route: Route, fn: () => Observable<any>): Observable<any>参数routeType: Route.fnType: () => Observable.返回值Observable<any>