目录

应用被拉起时如何获取外部传入参数

问题现象

外部启动应用，如何在应用中接收到外部传入的参数？如何把参数传到启动页面？例如首页根据参数显示不同的样式。

效果预览

背景知识

解决方案

实现思路：

  1. 在拉起方应用TestA中设置参数Want，调用startAbility()触发应用跳转。
    src/main/ets/pages/Index.ets：
    import { common, Want } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

@Entry
@Component
struct Index {
  message: string = 'Hello TestA';

  build() {
    Column() {
      Text(this.message)
        .id('HelloWorld')
        .fontSize($r('app.float.page_text_font_size'))
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        });

      // 跳转到TestB应用并携带msg参数
      Button('to TestB')
        .onClick(() => {
          let context: common.UIAbilityContext = this.getUIContext().getHostContext() as common.UIAbilityContext;
          let want: Want = {
            uri: 'link://www.testb.com',
            parameters: {
              msg: 'Hello TestB, I am TestA.'
            }
          };
          try {
            context.startAbility(want).then(() => {
              console.info('start ability success.');
            }).catch((err: BusinessError) => {
              console.error(`start ability failed. Code is ${err.code}, message is ${err.message}`);
            });
          } catch (paramError) {
            console.error(`Failed to start ability. Code is ${paramError.code}, message is ${paramError.message}`);
          }
        });
    }
    .justifyContent(FlexAlign.Center)
    .height('100%')
    .width('100%');
  }
}
  2. 在目标应用TestB的module.json5配置文件中的skills标签下新增以下skill对象，用于被其他应用访问。
    src/main/module.json5：
    {
  "actions": [
    // actions不能为空，actions为空会造成目标方匹配失败。
    "ohos.want.action.viewData"
  ],
  "uris": [
    {
      // scheme必选，可以自定义，以link为例，需要替换为实际的scheme
      "scheme": "link",
      // host必选，配置待匹配的域名
      "host": "www.testb.com"
    }
  ]
}
  3. 目标应用TestB是冷启动则在onCreate()中接收外部传入的参数Want，是热启动则在onNewWant()中接收外部传入的参数Want。
  4. 目标应用TestB将接收到的Want参数存入LocalStorage实例中。
    src/main/ets/entryability/EntryAbility.ets：
    import { ConfigurationConstant, UIAbility, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';

const DOMAIN = 0x0000;

export default class EntryAbility extends UIAbility {
  onCreate(want: Want): void {
    try {
      this.context.getApplicationContext().setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET);
    } catch (err) {
      hilog.error(DOMAIN, 'testTag', 'Failed to set colorMode. Cause: %{public}s', JSON.stringify(err));
    }
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onCreate');
    // 应用冷启动，调用getAndSetParameter方法获取外部参数并存入
    this.getAndSetParameter(want);
  }

  onDestroy(): void {
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onDestroy');
  }

  onWindowStageCreate(windowStage: window.WindowStage): void {
    // Main window is created, set main page for this ability
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onWindowStageCreate');

    windowStage.loadContent('pages/Index', this.storage, (err) => {
      if (err.code) {
        hilog.error(DOMAIN, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err));
        return;
      }
      hilog.info(DOMAIN, 'testTag', 'Succeeded in loading the content.');
    });
  }

  onWindowStageDestroy(): void {
    // Main window is destroyed, release UI related resources
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onWindowStageDestroy');
  }

  onForeground(): void {
    // Ability has brought to foreground
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onForeground');
  }

  onBackground(): void {
    // Ability has back to background
    hilog.info(DOMAIN, 'testTag', '%{public}s', 'Ability onBackground');
  }

  onNewWant(want: Want) {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onNewWant');
    // 应用热启动，调用getAndSetParameter方法获取外部参数并存入
    this.getAndSetParameter(want);
  }

  // 获取LocalStorage实例
  storage: LocalStorage = new LocalStorage();

  // 获取外部参数并存入LocalStorage实例中
  getAndSetParameter(want: Want): void {
    let parameters = want.parameters;
    if (parameters === null || parameters === undefined) {
      console.error('获取外部参数失败');
      return;
    }
    let msg = want.parameters?.msg;
    this.storage.setOrCreate('msg', msg);
  }
};
  5. 目标应用TestB在页面中通过getSharedLocalStorage()获取LocalStorage实例。
  6. 目标应用TestB获取LocalStorage实例中的Want参数并使用。
    src/main/ets/pages/Index.ets：
    @Entry
@Component
struct Index {
  localStorage = this.getUIContext().getSharedLocalStorage();

  message: string = 'Hello TestB';
  @State msg: string = 'I am TestB';

  onPageShow(): void {
    let val: string = this.localStorage?.get('msg') as string;
    if (val === null || val === undefined) {
      return;
    }
    this.msg = val;
  }

  build() {
    Column() {
      Text(this.message)
        .fontSize($r('app.float.page_text_font_size'))
        .fontWeight(FontWeight.Bold);
      Text(this.msg)
        .fontSize(25)
        .fontWeight(FontWeight.Bold);
    }
    .justifyContent(FlexAlign.Center)
    .height('100%')
    .width('100%');
  }
}