Primeng menubar ng-模板开始和结束或不显示，即使在执行了示例中的相同操作后也是如此

npm install primeng --save
npm install primeicons --save

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MenubarModule } from 'primeng/menubar';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    MenubarModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

@import "~primeng/resources/themes/saga-blue/theme.css";
@import "~primeng/resources/primeng.min.css";

<p-menubar [model]="items"></p-menubar>

import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  items = [
    {
      label: 'File',
      icon: 'pi pi-fw pi-file',
      items: [
        { label: 'New', icon: 'pi pi-fw pi-plus' },
        { label: 'Open', icon: 'pi pi-fw pi-folder-open' }
      ]
    },
    {
      label: 'Edit',
      icon: 'pi pi-fw pi-pencil'
    }
  ];
}