Angular2 CanActivate

在路由器中實現：

export const MainRoutes: Route[] = [{
   path: '',
   children: [ {
      path: 'main',
      component: MainComponent ,
      canActivate : [CanActivateRoute]
   }]
}];

canActivateRoute 檔案：

@Injectable()
  export class  CanActivateRoute implements CanActivate{
  constructor(){}
  canActivate(next: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean {
     return true;
  }
}