HarmonyOS鸿蒙Next中使用Navigation做路由跳转，怎么实现从第一个页面跳转到第二个页面后，返回直接退出App

Navigation启动时，通过this.pathStack.pushPathByName直接跳转到MainPage界面； 添加路由拦截，当路由目标页面名称为navBar（Navigation首页名字）时，就跳转到MainPage界面； 设置Navigation属性hideNavBar为true，隐藏返回导航栏。

具体代码实现如下：

• MainPage代码：

import { router } from '@kit.ArkUI';

@Component
struct MainPage {
  pageName: string = '';
  pathStack: NavPathStack | undefined = undefined;

  build() {
    NavDestination() {
      Column() {
        Text('this is MainPage').fontSize(24)
        Button(`push Page`).width('80%').margin({ top: 10, bottom: 10 })
          .onClick(() => {
            this.pathStack?.pushPathByName('Page', '');
          })
        Button(`pop`).width('80%').margin({ top: 10, bottom: 10 })
          .onClick(() => {
            this.pathStack?.pop();
          })
      }
    }.title('MainPage')
    .onReady((context: NavDestinationContext) => {
      this.pageName = context.pathInfo.name;
      this.pathStack = context.pathStack;
    })
    .onBackPressed(): boolean {
      router.back();
      return true;
    }
  }
}

• Page代码：

@Component
struct Page {
  pageName: string = '';
  pathStack: NavPathStack | undefined = undefined;

  build() {
    NavDestination() {
      Column() {
        Text('this is Page').fontSize(24)
        Button(`pop`).width('80%').margin({ top: 10, bottom: 10 })
          .onClick(() => {
            this.pathStack?.pop();
          })
      }
    }.title('Page')
    .onReady((context: NavDestinationContext) => {
      this.pageName = context.pathInfo.name;
      this.pathStack = context.pathStack;
    })
  }
}

• Index代码（即启动页）：

import { promptAction } from '@kit.ArkUI';

@Entry
@Component
struct Index {
  pathStack: NavPathStack = new NavPathStack();
  @State hideNavBar: boolean = false

  aboutToAppear(): void {
    setTimeout(() => {
      this.pathStack.pushPathByName('MainPage', undefined, false);
      this.hideNavBar = true
      // 添加路由拦截功能
      this.pathStack.setInterception({
        willShow: (from: NavDestinationContext | NavBar, to: NavDestinationContext | NavBar,
          operation: NavigationOperation, isAnimated: boolean) => {
          // 如果返回到首页，就跳转为MainPage页面
          if (to == 'navBar') {
            promptAction.showToast({ message: '无法返回到首页' })
            this.pathStack.pushPathByName('MainPage', undefined, false);
          }
        }
      })
    }, 2000)
  }

  @Builder
  pagesMap(name: string, param: number) {
    if (name == 'MainPage') {
      MainPage()
    } else if (name == 'Page') {
      Page()
    }
  }

  build() {
    Navigation(this.pathStack) {
      Text('欢迎进入APP').fontSize(30)
    }.title('启动页')
    .hideNavBar(this.hideNavBar)
    .navDestination(this.pagesMap)
  }
}