啟動指定頁面

當PageAbility的啟動模式設置為單例時（具體設置方法和典型場景示例見[PageAbility的啟動模式]，缺省情況下是單實例模式），若PageAbility已被拉起，再次啟動PageAbility會觸發(fā)onNewWant回調（即非首次拉起）。應用開發(fā)者可以通過want傳遞啟動參數(shù)，例如開發(fā)者希望指定頁面啟動PageAbility，可以通過want中的parameters參數(shù)傳遞pages信息，具體示例代碼如下： 開發(fā)前請熟悉鴻蒙開發(fā)指導文檔 ：[gitee.com/li-shizhen-skin/harmony-os/blob/master/README.md]

調用方PageAbility的app.ets中或者page中，使用startAbility再次拉起PageAbility，通過want中的uri參數(shù)傳遞頁面信息：

import featureAbility from '@ohos.ability.featureAbility';
import Want from '@ohos.app.ability.Want';
import hilog from '@ohos.hilog';

const TAG: string = 'PagePageAbilityFirst';
const domain: number = 0xFF00;

(async (): Promise< void > = > {
  let wantInfo: Want = {
    bundleName: 'com.samples.famodelabilitydevelop',
    abilityName: 'com.samples.famodelabilitydevelop.PageAbilitySingleton',
    parameters: { page: 'pages/second' }
  };
  featureAbility.startAbility({ want: wantInfo }).then((data) = > {
    hilog.debug(domain, TAG, `restartAbility success : ${data}`);
  });
})()

在目標端PageAbility的onNewWant回調中獲取包含頁面信息的want參數(shù)：

// GlobalContext.ts 構造單例對象
export class GlobalContext {
  private constructor() {
  }

  private static instance: GlobalContext;
  private _objects = new Map< string, Object >();

  public static getContext(): GlobalContext {
    if (!GlobalContext.instance) {
      GlobalContext.instance = new GlobalContext();
    }
    return GlobalContext.instance;
  }

  getObject(value: string): Object | undefined {
    return this._objects.get(value);
  }

  setObject(key: string, objectClass: Object): void {
    this._objects.set(key, objectClass);
  }
}

import Want from '@ohos.app.ability.Want';
import featureAbility from '@ohos.ability.featureAbility';
import { GlobalContext } from '../utils/GlobalContext';

class PageAbilitySingleton {
  onNewWant(want: Want) {
    featureAbility.getWant().then((want) = > {
      GlobalContext.getContext().setObject('newWant', want);
    })
  }
}

export default new PageAbilitySingleton();

在目標端頁面的自定義組件中獲取包含頁面信息的want參數(shù)并根據(jù)uri做路由處理：

import Want from '@ohos.app.ability.Want';
import router from '@ohos.router';
import { GlobalContext } from '../../utils/GlobalContext';

@Entry
@Component
struct First {
  onPageShow() {
    let newWant = GlobalContext.getContext().getObject('newWant') as Want;
    if (newWant) {
      if (newWant.parameters) {
        if (newWant.parameters.page) {
          router.pushUrl({ url: newWant.parameters.page as string});
          GlobalContext.getContext().setObject("newWant", undefined)
        }
      }
    }
  }

  build() {
    Column() {
      Row() {
        Text($r('app.string.singleton_first_title'))
          .fontSize(24)
          .fontWeight(FontWeight.Bold)
          .textAlign(TextAlign.Start)
          .margin({ top: 12, bottom: 11, right: 24, left: 24 })
      }
      .width('100%')
      .height(56)
      .justifyContent(FlexAlign.Start)

      Image($r('app.media.pic_empty'))
        .width(120)
        .height(120)
        .margin({ top: 224 })

      Text($r('app.string.no_content'))
        .fontSize(14)
        .margin({ top: 8, bottom: 317, right: 152, left: 152 })
        .fontColor($r('app.color.text_color'))
        .opacity(0.4)
    }
    .width('100%')
    .height('100%')
    .backgroundColor($r('app.color.backGrounding'))
  }
}

當PageAbility的啟動模式設置為多實例模式或為首次啟動單例模式的PageAbility時（具體設置方法和典型場景示例見[PageAbility的啟動模式]），在調用方PageAbility中，通過want中的parameters參數(shù)傳遞要啟動的指定頁面的pages信息，調用startAbility()方法啟動PageAbility。被調用方可以在onCreate中使用featureAbility的getWant方法獲取want，再通過調用router.pushUrl實現(xiàn)啟動指定頁面。

調用方的頁面中實現(xiàn)按鈕點擊觸發(fā)startAbility方法啟動目標端PageAbility，startAbility方法的入?yún)ant中攜帶指定頁面信息，示例代碼如下：

import featureAbility from '@ohos.ability.featureAbility';
import Want from '@ohos.app.ability.Want';
import { BusinessError } from '@ohos.base';
import fs from '@ohos.file.fs';
import promptAction from '@ohos.promptAction';
import worker from '@ohos.worker';
import hilog from '@ohos.hilog';

const TAG: string = 'PagePageAbilityFirst';
const domain: number = 0xFF00;

@Entry
@Component
struct PagePageAbilityFirst {
  build() {
    Column() {
      //...
      List({ initialIndex: 0 }) {
        //...
        ListItem() {
          Flex({ justifyContent: FlexAlign.SpaceBetween, alignContent: FlexAlign.Center }) {
          //...
          }
          .onClick(() = > {
            let want: Want = {
              bundleName: 'com.samples.famodelabilitydevelop',
              abilityName: 'com.samples.famodelabilitydevelop.PageAbilityStandard',
              parameters: { page: 'pages/first' }
            };
            featureAbility.startAbility({ want: want }).then((data) = > {
              hilog.info(domain, TAG, `startAbility finish:${data}`);
            }).catch((err: BusinessError) = > {
              hilog.info(domain, TAG, `startAbility failed errcode:${err.code}`);
            })
          })
        }
        //...
        ListItem() {
          Flex({ justifyContent: FlexAlign.SpaceBetween, alignContent: FlexAlign.Center }) {
          //...
          }
          .onClick(() = > {
            let want: Want = {
              bundleName: 'com.samples.famodelabilitydevelop',
              abilityName: 'com.samples.famodelabilitydevelop.PageAbilityStandard',
              parameters: { page: 'pages/second' }
            };
            featureAbility.startAbility({ want: want }).then((data) = > {
              hilog.info(domain, TAG, `startAbility finish:${data}`);
            }).catch((err: BusinessError) = > {
              hilog.info(domain, TAG, `startAbility failed errcode:${err.code}`);
            })
          })
        }
        //...
      }
      //...
    }
    //...
  }
}

`HarmonyOS與OpenHarmony鴻蒙文檔籽料：mau123789是v直接拿`

目標端PageAbility的onCreate生命周期回調中通過featureAbility的getWant方法獲取want，并對參數(shù)進行解析，實現(xiàn)指定頁面拉起：

import featureAbility from '@ohos.ability.featureAbility';
import router from '@ohos.router';

class PageAbilityStandard {
  onCreate() {
    featureAbility.getWant().then((want) = > {
      if (want.parameters) {
        if (want.parameters.page) {
          router.pushUrl({ url: want.parameters.page as string });
        }
      }
    })
  }
}

export default new PageAbilityStandard();

審核編輯 黃宇