getContext

The getContext API enables you to obtain the context of the ability (either UIAbilityContext or ExtensionContext) on the current page.

NOTE

• This API is supported since API version 9.
• This API applies only to the stage model.

getContext(component?: Object):Context

Obtains the Context object associated with an ability on the page.

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

System capability: SystemCapability.ArkUI.ArkUI.Full

Parameters

Name	Type	Mandatory	Description
component	Object	No	Ability instance. If no component is passed in or the passed-in parameter type is invalid, the default context is returned. The default context is the context obtained by tracing the call chain of the API. If this API is used in an asynchronous callback or not initially called on the current page, the context of the instance may fail to be traced. In this case, undefined is returned.

Return value

Type	Description
Context	Context of the ability. The context type depends on the ability type. For example, if this API is called on a page of the UIAbility, the return value type is UIAbilityContext; if this API is called on a page of the ExtensionAbility, the return value type is ExtensionContext.

Example

Load a page by calling windowStage.loadContent in the UIAbility.

NOTE

To avoid confusion with instances, it is recommended that you obtain a UIContext instance using the getUIContext API, and then call getContext bound to the context through the getHostContext API.

// EntryAbility.ets
import { UIAbility, AbilityConstant, Want } from '@kit.AbilityKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { window } from '@kit.ArkUI';

export default class EntryAbility extends UIAbility {
  onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
  }

  onDestroy() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy');
  }

  onWindowStageCreate(windowStage: window.WindowStage) {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');

    windowStage.loadContent('pages/Index', (err, data) => {
      if (err.code) {
        hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
        return;
      }
      hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
    });
  }

  onWindowStageDestroy() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageDestroy');
  }

  onForeground() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onForeground');
  }

  onBackground() {
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onBackground');
  }
}

In Index.ets, getContext is used to obtain the context. In this example, the return value type is UIAbilityContext.

//pages/Index.ets
@Entry
@Component
struct Index {
  @State message: string = 'Hello World'

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .onClick(() => {
            // You are advised to use this.getUIContext().getHostContext().
            let context : Context = getContext(this) as Context
            console.info("CacheDir:" + context.cacheDir)
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}