Obtaining UIAbility Context

In HarmonyOS development, you can retrieve the current ability's context directly within EntryAbility, or obtain the UIAbility instance information from any Page component.

Configuring Want Parameters

The Want object contains several configuration parameters. The two essential parameters are:

• bundleName: The target application's bundle identifier
• abilityName: The target UIAbility's name

Initiating Navigation

Use context.startAbility(want) to navigate to another UIAbility. The implementation follows:

import common from '@ohos.app.ability.common';

@Component
struct MainPage {
  build() {
    Button('Navigate')
      .onClick(() => {
        this.launchTargetAbility();
      });
  }

  private launchTargetAbility(): void {
    const abilityContext = getContext(this) as common.UIAbilityContext;

    const navigationParams = {
      deviceId: '',
      bundleName: 'com.example.app',
      abilityName: 'TargetAbility',
    };

    abilityContext.startAbility(navigationParams)
      .then((result) => {
        console.log('Navigation successful:', JSON.stringify(result));
      })
      .catch((error) => {
        console.error('Navigation failed:', error.code, error.message);
      });
  }
}

Note: When using the previewer, ensure the target UIAbility has visible: true configured in module.json5 under the exported: true property. Without this configuration, the application may crash. This requirement applies to simulator testing.

Navigation Methods Overview

HarmonyOS provides multiple navigation approaches:

1. Internal UIAbility Launch: Start another UIAbility within the same applicasion.
2. Internal UIAbility with Result: Launch an internal UIAbility and receive a callback result.
3. External Application Launch: Start a UIAbility in another application, supporting both explicit and implicit Want configurations.
   • Explicit Want: Precisely match a specific application
   • Implicit Want: Use fuzzy matching to select from multiple eligible UIAbilities
4. Cross-Application Result: Launch an external UIAbility and retrieve return data.
5. Call Interface: Enable UIAbility interaction through IPC, available only for system applications.

Launching System Applications

Opening System Gallery

const systemWant = {
  deviceId: '',
  bundleName: '',
  abilityName: '',
  uri: '',
  flags: wantConstant.Flags.FLAG_AUTH_READ_URI_PERMISSION,
  action: 'android.settings.SETTINGS',
  parameters: {},
  entities: []
};

this.context.startAbility(systemWant, (error) => {
  if (error.code) {
    console.log('startAbility failed, error.code:', JSON.stringify(error.code),
      'error.message:', JSON.stringify(error.message));
    return;
  }
  console.log('System application launched successfully');
});

System Settings Actions

The following table lists common system settings actions available in HarmonyOS 3.1 and 4.0:

Cross-Device Navigation

Cross-device ability launching between simulators is not supported in the current version. Attempting such navigation may result in error code 16000009 with message "Cannot operate in wukong mode."