Context

The Context module, inherited from BaseContext, provides context for abilities or applications, including access to application-specific resources.

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.
• The APIs of this module can be used only in the stage model.

Inheritance and Holding Relationships of Different Context Types

• Inheritance relationships among different types of context

  

• Holding relationships among different types of context

  

Modules to Import

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

Properties

System capability: SystemCapability.Ability.AbilityRuntime.Core

Context.createModuleContext^(deprecated)

createModuleContext(moduleName: string): Context

Creates the context based on the module name.

NOTE

This API is deprecated since API version 12. You are advised to use application.createModuleContext instead.

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Return value

Error codes

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

Example

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

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.log('MyAbility onCreate');
    let moduleContext: common.Context;
    try {
      moduleContext = this.context.createModuleContext('entry');
    } catch (error) {
      console.error(`createModuleContext failed, error.code: ${(error as BusinessError).code}, error.message: ${(error as BusinessError).message}`);
    }
  }
}

NOTE

Only the context of other modules in the current application and the context of the intra-application HSP can be obtained. The context of other applications cannot be obtained.

Context.getApplicationContext

getApplicationContext(): ApplicationContext

Obtains the context of this application.

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Return value

Error codes

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

Example

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

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.log('MyAbility onCreate');
    let applicationContext: common.Context;
    try {
      applicationContext = this.context.getApplicationContext();
    } catch (error) {
      console.error(`getApplicationContext failed, error.code: ${(error as BusinessError).code}, error.message: ${(error as BusinessError).message}`);
    }
  }
}

Context.getGroupDir¹⁰⁺

getGroupDir(dataGroupID: string): Promise<string>

Obtains the shared directory based on a group ID. This API uses a promise to return the result.

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Return value

Error codes

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

Example

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

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.log('MyAbility onCreate');
    let groupId = "1";
    let getGroupDirContext: common.Context = this.context;
    try {
      getGroupDirContext.getGroupDir(groupId).then(data => {
        console.log("getGroupDir result:" + data);
      })
    } catch (error) {
      console.error(`getGroupDirContext failed, error.code: ${(error as BusinessError).code}, error.message: ${(error as BusinessError).message}`);
    }
  }
}

Context.getGroupDir¹⁰⁺

getGroupDir(dataGroupID: string, callback: AsyncCallback<string>): void

Obtains the shared directory based on a group ID. This API uses an asynchronous callback to return the result.

Atomic service API: This API can be used in atomic services since API version 11.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Error codes

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

Example

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

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.log('MyAbility onCreate');
    let getGroupDirContext: common.Context = this.context;

    getGroupDirContext.getGroupDir("1", (err: BusinessError, data) => {
      if (err) {
        console.error(`getGroupDir faile, err: ${JSON.stringify(err)}`);
      } else {
        console.log(`getGroupDir result is: ${JSON.stringify(data)}`);
      }
    });
  }
}

Context.createAreaModeContext¹⁸⁺

createAreaModeContext(areaMode: contextConstant.AreaMode): Context

Creates the context for this application based on a data encryption level. This is required when an application needs to store different types of information in different directories. The application can obtain the corresponding directory.

Atomic service API: This API can be used in atomic services since API version 18.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Return value

Error codes

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

Example

import { common, UIAbility, contextConstant } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';

export default class EntryAbility extends UIAbility {
  onCreate() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
    let areaMode: contextConstant.AreaMode = contextConstant.AreaMode.EL2;
    let areaModeContext: common.Context;
    try {
      areaModeContext = this.context.createAreaModeContext(areaMode);
    } catch (error) {
      hilog.error(0x0000, 'testTag', 'createAreaModeContext error is:%{public}s', JSON.stringify(error));
    }
  }
}

Context.createDisplayContext¹⁵⁺

createDisplayContext(displayId: number): Context

Creates the context based on the specified display ID, so as to obtain and use other application contexts with screen information (including ScreenDensity and Direction).

Atomic service API: This API can be used in atomic services since API version 15.

System capability: SystemCapability.Ability.AbilityRuntime.Core

Parameters

Return value

Error codes

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

Example

import { common, UIAbility } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';

export default class EntryAbility extends UIAbility {
  onCreate() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
    let displayContext: common.Context;
    try {
      displayContext = this.context.createDisplayContext(0);
    } catch (error) {
      hilog.error(0x0000, 'testTag', 'createDisplayContext error is:%{public}s', JSON.stringify(error));
    }
  }
}