harmony 鸿蒙ApplicationContext (System API)

2025-06-12
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ApplicationContext (System API)

The ApplicationContext module, inherited from Context, provides application-level context capabilities, including APIs for registering and deregistering the lifecycle of application components.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

This topic describes only system APIs provided by the module. For details about its public APIs, see ApplicationContext.

Modules to Import

import { common } from '@kit.AbilityKit';

Instructions

Before calling any APIs in ApplicationContext, obtain an ApplicationContext instance through the context instance.

ApplicationContext.preloadUIExtensionAbility¹²⁺

preloadUIExtensionAbility(want: Want): Promise<void>

Preloads a UIExtensionAbility instance.

The preloaded UIExtensionAbility instance is sent to the onCreate lifecycle of the UIExtensionAbility and waits to be loaded by the current application.

A UIExtensionAbility instance can be preloaded for multiple times. Each time a preloaded UIExtensionAbility instance is loaded, the next preloaded UIExtensionAbility instance is sent to the onCreate lifecycle of the UIExtensionAbility.

System capability: SystemCapability.Ability.AbilityRuntime.Core

System API: This is a system API.

Name	Type	Mandatory	Description
want	Want	Yes	Want information of the UIExtensionAbility.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Error codes

For details about the error codes, see Universal Error Codes and Ability Error Codes.

ID	Error Message
401	Parameter error. Possible causes: 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types.
16000001	The specified ability does not exist.
16000002	Incorrect ability type.
16000004	Failed to start the invisible ability.
16200011	The context does not exist.
16000050	Internal error.

Example

import { UIAbility, Want } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

export default class EntryAbility extends UIAbility {
  onCreate() {
    let want: Want = {
      bundleName: 'com.ohos.uiextensionprovider',
      abilityName: 'UIExtensionProvider',
      moduleName: 'entry',
      parameters: {
        // The value must be the same as the value of type in the module.json5 file of the UIExtensionAbility.
        'ability.want.params.uiExtensionType': 'sys/commonUI'
      }
    };
    try {
      let applicationContext = this.context.getApplicationContext();
      applicationContext.preloadUIExtensionAbility(want)
        .then(() => {
          // Carry out normal service processing.
          console.info('preloadUIExtensionAbility succeed');
        })
        .catch((err: BusinessError) => {
          // Process service logic errors.
          console.error('preloadUIExtensionAbility failed');
        });
    } catch (err) {
      // Process input parameter errors.
      let code = (err as BusinessError).code;
      let message = (err as BusinessError).message;
      console.error(`preloadUIExtensionAbility failed. code: ${code}, msg: ${message}`);
    }
  }
}