HarmonyOS 鸿蒙Next 某些页面设置横竖屏

为您提供如下demo：

1. 首先打开entry下面的module.json5文件，在abilities节点下添加一个orientation的属性：

   "orientation": 'unspecified'
   

2. 第一个页面：

   import { router } from '[@kit](/user/kit).ArkUI';
   [@Entry](/user/Entry)
   [@Component](/user/Component)
   struct aboutScreen1 {
     @State message: string = '';
   
     build() {
       Column() {
         Text('首页，点我跳转')
           .fontSize(30)
           .textAlign(TextAlign.Center)
           .width('100%')
           .fontWeight(500)
           .height('100%')
           .onClick(() => {
             router.pushUrl({url: "pages/aboutScreen2" })
           })
       }
       .justifyContent(FlexAlign.Center)
       .width('100%')
       .backgroundColor(Color.White)
       .height('100%')
     }
   }
   

3. 第二个页面：

   import { router, window } from '[@kit](/user/kit).ArkUI';
   import { BusinessError } from '[@kit](/user/kit).BasicServicesKit';
   
   [@Entry](/user/Entry)
   [@Component](/user/Component)
   struct aboutScreen1 {
     @State message: string = '';
   
     aboutToAppear(): void {
       let orientation = window.Orientation.LANDSCAPE
       this.setScreenOrientation(orientation)
     }
   
     aboutToDisappear(): void {
       let orientation = window.Orientation.PORTRAIT
       this.setScreenOrientation(orientation)
     }
   
     setScreenOrientation(orientation: window.Orientation) {
       let windowClass: window.Window | undefined = undefined;
       try{
         let promise = window.getLastWindow(getContext())
         promise.then((data) => {
           windowClass = data
           windowClass.setPreferredOrientation(orientation)
         }).catch((err: BusinessError) => {
           console.error('getLastWindow error')
         })
       } catch (e) {
         console.error('setScreenOrientation error')
       }
     }
   
     build() {
       Column() {
         Text('我横屏啦')
           .fontSize(30)
           .textAlign(TextAlign.Center)
           .width('100%')
           .fontWeight(500)
           .height('50%')
       }
       .justifyContent(FlexAlign.Center)
       .width('100%')
       .backgroundColor(Color.White)
       .height('100%')
     }
   }