# AbilityContext

The **AbilityContext** module, inherited from **Context**, implements the context for abilities.

This module provides APIs for accessing ability-specific resources. You can use the APIs to start and terminate an ability, obtain the caller interface, and request permissions from users by displaying a dialog box.

> **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.

## Usage

Before using the **AbilityContext** module, you must define a child class that inherits from **Ability**.

```ts
import UIAbility from '@ohos.app.ability.UIAbility';

let context = undefined;
class EntryAbility extends UIAbility {
    onWindowStageCreate(windowStage) {
        context = this.context;
    }
}
```

## Attributes

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

| Name| Type| Readable| Writable| Description|
| -------- | -------- | -------- | -------- | -------- |
| abilityInfo | [AbilityInfo](js-apis-bundleManager-abilityInfo.md) | Yes| No| Ability information.|
| currentHapModuleInfo | [HapModuleInfo](js-apis-bundleManager-hapModuleInfo.md) | Yes| No| Information about the current HAP.|
| config | [Configuration](js-apis-application-configuration.md) | Yes| No| Configuration information.|

## AbilityContext.startAbility

startAbility(want: Want, callback: AsyncCallback<void>): void;

Starts an ability. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback<void> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    bundleName: "com.example.myapplication",
    abilityName: "MyAbility"
  };

  try {
    this.context.startAbility(want, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startAbility succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbility

startAbility(want: Want, options: StartOptions, callback: AsyncCallback<void>): void;

Starts an ability with the start options specified. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md)  | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-application-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback<void> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var options = {
    windowMode: 0
  };

  try {
    this.context.startAbility(want, options, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startAbility succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startAbility

startAbility(want: Want, options?: StartOptions): Promise<void>;

Starts an ability. This API uses a promise to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-application-startOptions.md) | No| Parameters used for starting the ability.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise<void> | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    bundleName: "com.example.myapplication",
    abilityName: "MyAbility"
  };
  var options = {
  	windowMode: 0,
  };

  try {
    this.context.startAbility(want, options)
      .then((data) => {
        // Carry out normal service processing.
        console.log('startAbility succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityForResult

startAbilityForResult(want: Want, callback: AsyncCallback<AbilityResult>): void;

Starts an ability. After the ability is started, you can call [terminateSelfWithResult](#abilitycontextterminateselfwithresult) to terminate the ability and return the result to the caller. If an exception occurs, for example, the ability is killed, exception information is returned to the caller. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want |[Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback<[AbilityResult](js-apis-inner-ability-abilityResult.md)> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };

  try {
    this.context.startAbilityForResult(want, (error, result) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityForResult failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log("startAbilityForResult succeed, result.resultCode = " +
        result.resultCode)
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startAbilityForResult

startAbilityForResult(want: Want, options: StartOptions, callback: AsyncCallback<AbilityResult>): void;

Starts an ability with the start options specified. After the ability is started, you can call [terminateSelfWithResult](#abilitycontextterminateselfwithresult) to terminate the ability and return the result to the caller. If an exception occurs, for example, the ability is killed, exception information is returned to the caller. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want |[Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-application-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback<[AbilityResult](js-apis-inner-ability-abilityResult.md)> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var options = {
    windowMode: 0,
  };

  try {
    this.context.startAbilityForResult(want, options, (error, result) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityForResult failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log("startAbilityForResult succeed, result.resultCode = " +
        result.resultCode)
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityForResult

startAbilityForResult(want: Want, options?: StartOptions): Promise<AbilityResult>;

Starts an ability. After the ability is started, you can call [terminateSelfWithResult](#abilitycontextterminateselfwithresult) to terminate the ability and return the result to the caller. If an exception occurs, for example, the ability is killed, exception information is returned to the caller. This API uses a promise to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| options | [StartOptions](js-apis-application-startOptions.md) | No| Parameters used for starting the ability.|


**Return value**

| Type| Description|
| -------- | -------- |
| Promise<[AbilityResult](js-apis-inner-ability-abilityResult.md)> | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    bundleName: "com.example.myapplication",
    abilityName: "MyAbility"
  };
  var options = {
  	windowMode: 0,
  };

  try {
    this.context.startAbilityForResult(want, options)
      .then((result) => {
        // Carry out normal service processing.
        console.log("startAbilityForResult succeed, result.resultCode = " + result.resultCode);
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startAbilityForResult failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startAbilityForResultWithAccount

startAbilityForResultWithAccount(want: Want, accountId: number, callback: AsyncCallback\<AbilityResult>): void;

Starts an ability with the account ID specified. This API uses an asynchronous callback to return the result when the ability is terminated.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| callback | AsyncCallback\<[AbilityResult](js-apis-inner-ability-abilityResult.md)\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startAbilityForResultWithAccount(want, accountId, (error, result) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityForResultWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log("startAbilityForResultWithAccount succeed, result.resultCode = " +
        result.resultCode)
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityForResultWithAccount

startAbilityForResultWithAccount(want: Want, accountId: number, options: StartOptions, callback: AsyncCallback\<void\>): void;

Starts an ability with the start options and account ID specified. This API uses an asynchronous callback to return the result when the ability is terminated.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| options | [StartOptions](js-apis-application-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;
  var options = {
    windowMode: 0
  };

  try {
    this.context.startAbilityForResultWithAccount(want, accountId, options, (error, result) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityForResultWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log("startAbilityForResultWithAccount succeed, result.resultCode = " +
        result.resultCode)
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityForResultWithAccount

startAbilityForResultWithAccount(want: Want, accountId: number, options?: StartOptions): Promise\<AbilityResult\>;

Starts an ability with the account ID specified. This API uses a promise to return the result when the ability is terminated.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| options | [StartOptions](js-apis-application-startOptions.md) | No| Parameters used for starting the ability.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;[AbilityResult](js-apis-inner-ability-abilityResult.md)&gt; | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;
  var options = {
    windowMode: 0
  };

  try {
    this.context.startAbilityForResultWithAccount(want, accountId, options)
      .then((result) => {
        // Carry out normal service processing.
        console.log("startAbilityForResultWithAccount succeed, result.resultCode = " +
          result.resultCode)
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startAbilityForResultWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```
## AbilityContext.startServiceExtensionAbility

startServiceExtensionAbility(want: Want, callback: AsyncCallback\<void>): void;

Starts a ServiceExtensionAbility. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };

  try {
    this.context.startServiceExtensionAbility(want, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startServiceExtensionAbility succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startServiceExtensionAbility

startServiceExtensionAbility(want: Want): Promise\<void>;

Starts a ServiceExtensionAbility. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };

  try {
    this.context.startServiceExtensionAbility(want)
      .then((data) => {
        // Carry out normal service processing.
        console.log('startServiceExtensionAbility succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startServiceExtensionAbilityWithAccount

startServiceExtensionAbilityWithAccount(want: Want, accountId: number, callback: AsyncCallback\<void>): void;

Starts a ServiceExtensionAbility with the account ID specified. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startServiceExtensionAbilityWithAccount(want, accountId, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startServiceExtensionAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startServiceExtensionAbilityWithAccount succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startServiceExtensionAbilityWithAccount

startServiceExtensionAbilityWithAccount(want: Want, accountId: number): Promise\<void>;

Starts a ServiceExtensionAbility with the account ID specified. This API uses a promise to return the result.

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startServiceExtensionAbilityWithAccount(want, accountId)
      .then((data) => {
        // Carry out normal service processing.
        console.log('startServiceExtensionAbilityWithAccount succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startServiceExtensionAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```
## AbilityContext.stopServiceExtensionAbility

stopServiceExtensionAbility(want: Want, callback: AsyncCallback\<void>): void;

Stops a ServiceExtensionAbility in the same application. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };

  try {
    this.context.startAbility(want, (error) => {
      if (error.code != 0) {
        console.log("start ability fail, err: " + JSON.stringify(err));
      }
    })

    this.context.stopServiceExtensionAbility(want, (error) => {
      if (error.code != 0) {
        // Process service logic errors.
        console.log('stopServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('stopServiceExtensionAbility succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.stopServiceExtensionAbility

stopServiceExtensionAbility(want: Want): Promise\<void>;

Stops a ServiceExtensionAbility in the same application. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };

  try {
    this.context.startAbility(want, (error) => {
      if (error.code != 0) {
        console.log("start ability fail, err: " + JSON.stringify(err));
      }
    })

    this.context.stopServiceExtensionAbility(want)
      .then((data) => {
        // Carry out normal service processing.
        console.log('stopServiceExtensionAbility succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('stopServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.stopServiceExtensionAbilityWithAccount

stopServiceExtensionAbilityWithAccount(want: Want, accountId: number, callback: AsyncCallback\<void>): void;

Stops a ServiceExtensionAbility in the same application with the account ID specified. This API uses an asynchronous callback to return the result.

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startAbilityWithAccount(want, accountId, (error) => {
      if (error.code != 0) {
        console.log("start ability fail, err: " + JSON.stringify(err));
      }
    })

    this.context.stopServiceExtensionAbilityWithAccount(want, accountId, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('stopServiceExtensionAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('stopServiceExtensionAbilityWithAccount succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.stopServiceExtensionAbilityWithAccount

stopServiceExtensionAbilityWithAccount(want: Want, accountId: number): Promise\<void>;

Stops a ServiceExtensionAbility in the same application with the account ID specified. This API uses a promise to return the result.

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startAbilityWithAccount(want, accountId, (error) => {
      if (error.code != 0) {
        console.log("start ability fail, err: " + JSON.stringify(err));
      }
    })

    this.context.stopServiceExtensionAbilityWithAccount(want, accountId)
      .then((data) => {
        // Carry out normal service processing.
        console.log('stopServiceExtensionAbilityWithAccount succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('stopServiceExtensionAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.terminateSelf

terminateSelf(callback: AsyncCallback&lt;void&gt;): void;

Terminates this ability. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  this.context.terminateSelf((error) => {
    if (error.code) {
      // Process service logic errors.
      console.log('terminateSelf failed, error.code: ' + JSON.stringify(error.code) +
        ' error.message: ' + JSON.stringify(error.message));
      return;
    }
    // Carry out normal service processing.
    console.log('terminateSelf succeed');
  });
  ```


## AbilityContext.terminateSelf

terminateSelf(): Promise&lt;void&gt;;

Terminates this ability. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  this.context.terminateSelf().then((data) => {
    // Carry out normal service processing.
    console.log('terminateSelf succeed');
  }).catch((error) => {
    // Process service logic errors.
    console.log('terminateSelf failed, error.code: ' + JSON.stringify(error.code) +
      ' error.message: ' + JSON.stringify(error.message));
  });
  ```


## AbilityContext.terminateSelfWithResult

terminateSelfWithResult(parameter: AbilityResult, callback: AsyncCallback&lt;void&gt;): void;

Terminates this ability. If the ability is started by calling [startAbilityForResult](#abilitycontextstartabilityforresult), the result is returned to the caller in the form of a callback when **terminateSelfWithResult** is called. Otherwise, no result is returned to the caller when **terminateSelfWithResult** is called.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| parameter | [AbilityResult](js-apis-inner-ability-abilityResult.md) | Yes| Information returned to the caller.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    bundleName: "com.extreme.myapplication",
    abilityName: "SecondAbility"
  }
  var resultCode = 100;
  // AbilityResult information returned to the caller.
  var abilityResult = {
    want,
    resultCode
  }

  try {
    this.context.terminateSelfWithResult(abilityResult, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('terminateSelfWithResult failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('terminateSelfWithResult succeed');
    });
  } catch (paramError) {
      // Process input parameter errors.
      console.log('error.code: ' + JSON.stringify(paramError.code) +
        ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.terminateSelfWithResult

terminateSelfWithResult(parameter: AbilityResult): Promise&lt;void&gt;;
Terminates this ability. If the ability is started by calling [startAbilityForResult](#abilitycontextstartabilityforresult), the result is returned to the caller in the form of a promise when **terminateSelfWithResult** is called. Otherwise, no result is returned to the caller when **terminateSelfWithResult** is called.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| parameter | [AbilityResult](js-apis-inner-ability-abilityResult.md) | Yes| Information returned to the caller.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).


**Example**

  ```ts
  var want = {
    bundleName: "com.extreme.myapplication",
    abilityName: "SecondAbility"
  }
  var resultCode = 100;
  // AbilityResult information returned to the caller.
  var abilityResult = {
    want,
    resultCode
  }

  try {
    this.context.terminateSelfWithResult(abilityResult)
      .then((data) => {
        // Carry out normal service processing.
        console.log('terminateSelfWithResult succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('terminateSelfWithResult failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.connectServiceExtensionAbility

connectServiceExtensionAbility(want: Want, options: ConnectOptions): number;

Uses the **AbilityInfo.AbilityType.SERVICE** template to connect this ability to another ability.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| options | [ConnectOptions](js-apis-inner-ability-connectOptions.md) | Yes| Parameters for the connection.|

**Return value**

| Type| Description|
| -------- | -------- |
| number | Result code of the ability connection.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var options = {
    onConnect(elementName, remote) { console.log('----------- onConnect -----------') },
    onDisconnect(elementName) { console.log('----------- onDisconnect -----------') },
    onFailed(code) { console.log('----------- onFailed -----------') }
  }

  var connection = null;
  try {
    connection = this.context.connectServiceExtensionAbility(want, options);
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.connectServiceExtensionAbilityWithAccount

connectServiceExtensionAbilityWithAccount(want: Want, accountId: number, options: ConnectOptions): number;

Uses the **AbilityInfo.AbilityType.SERVICE** template to connect this ability to another ability with the account ID specified.

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| options | [ConnectOptions](js-apis-inner-ability-connectOptions.md) | Yes| Parameters for the connection.|

**Return value**

| Type| Description|
| -------- | -------- |
| number | Result code of the ability connection.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;
  var options = {
    onConnect(elementName, remote) { console.log('----------- onConnect -----------') },
    onDisconnect(elementName) { console.log('----------- onDisconnect -----------') },
    onFailed(code) { console.log('----------- onFailed -----------') }
  }

  var connection = null;
  try {
    connection = this.context.connectServiceExtensionAbilityWithAccount(want, accountId, options);
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.disconnectServiceExtensionAbility

disconnectServiceExtensionAbility(connection: number): Promise\<void>;

Disconnects a connection. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| connection | number | Yes| Result code of the ability connection.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise\<void> | Promise used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  // connection is the return value of connectServiceExtensionAbility.
  var connection = 1;

  try {
    this.context.disconnectServiceExtensionAbility(connection)
      .then((data) => {
        // Carry out normal service processing.
        console.log('disconnectServiceExtensionAbility succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('disconnectServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.disconnectServiceExtensionAbility

disconnectServiceExtensionAbility(connection: number, callback:AsyncCallback\<void>): void;

Disconnects a connection. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| connection | number | Yes| Result code of the ability connection.|
| callback | AsyncCallback\<void> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  // connection is the return value of connectServiceExtensionAbility.
  var connection = 1;

  try {
    this.context.disconnectServiceExtensionAbility(connection, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('disconnectServiceExtensionAbility failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('disconnectServiceExtensionAbility succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startAbilityByCall

startAbilityByCall(want: Want): Promise&lt;Caller&gt;;

Starts an ability in the foreground or background and obtains the caller object for communicating with the ability.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - The rules for using this API in the same-device and cross-device scenarios are different. For details, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Information about the ability to start, including **abilityName**, **moduleName**, **bundleName**, **deviceId** (optional), and **parameters** (optional). If **deviceId** is left blank or null, the local ability is started. If **parameters** is left blank or null, the ability is started in the background.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;Caller&gt; | Promise used to return the caller object to communicate with.|

**Example**

  Start an ability in the background.

  ```ts
  var caller = undefined;

  // Start an ability in the background by not passing parameters.
  var wantBackground = {
      bundleName: "com.example.myservice",
      moduleName: "entry",
      abilityName: "EntryAbility",
      deviceId: ""
  };

  try {
    this.context.startAbilityByCall(wantBackground)
      .then((obj) => {
        // Carry out normal service processing.
        caller = obj;
        console.log('startAbilityByCall succeed');
      }).catch((error) => {
        // Process service logic errors.
        console.log('startAbilityByCall failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

  Start an ability in the foreground.

  ```ts
  var caller = undefined;

  // Start an ability in the foreground with ohos.aafwk.param.callAbilityToForeground in parameters set to true.
  var wantForeground = {
      bundleName: "com.example.myservice",
      moduleName: "entry",
      abilityName: "EntryAbility",
      deviceId: "",
      parameters: {
        "ohos.aafwk.param.callAbilityToForeground": true
      }
  };

  try {
    this.context.startAbilityByCall(wantForeground)
      .then((obj) => {
        // Carry out normal service processing.
        caller = obj;
        console.log('startAbilityByCall succeed');
      }).catch((error) => {
        // Process service logic errors.
        console.log('startAbilityByCall failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.startAbilityWithAccount

startAbilityWithAccount(want: Want, accountId: number, callback: AsyncCallback\<void\>): void;

Starts an ability with the account ID specified. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;

  try {
    this.context.startAbilityWithAccount(want, accountId, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startAbilityWithAccount succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityWithAccount

startAbilityWithAccount(want: Want, accountId: number, options: StartOptions, callback: AsyncCallback\<void\>): void;

Starts an ability with the account ID and start options specified. This API uses an asynchronous callback to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| options | [StartOptions](js-apis-application-startOptions.md) | Yes| Parameters used for starting the ability.|
| callback | AsyncCallback\<void\> | Yes| Callback used to return the result.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;
  var options = {
    windowMode: 0
  };

  try {
    this.context.startAbilityWithAccount(want, accountId, options, (error) => {
      if (error.code) {
        // Process service logic errors.
        console.log('startAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
        return;
      }
      // Carry out normal service processing.
      console.log('startAbilityWithAccount succeed');
    });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```


## AbilityContext.startAbilityWithAccount

startAbilityWithAccount(want: Want, accountId: number, options?: StartOptions): Promise\<void\>;

Starts an ability with the account ID specified. This API uses a promise to return the result.

Observe the following when using this API:
 - If an application running in the background needs to call this API to start an ability, it must have the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission.
 - If **visible** of the target ability is **false** in cross-application scenarios, the caller must have the **ohos.permission.START_INVISIBLE_ABILITY** permission.
 - For details about the startup rules for the components in the stage model, see [Component Startup Rules (Stage Model)](../../application-models/component-startup-rules.md).

**Required permissions**: ohos.permission.INTERACT_ACROSS_LOCAL_ACCOUNTS (required only when the account ID is not the current user)

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| want | [Want](js-apis-application-want.md) | Yes| Want information about the target ability.|
| accountId | number | Yes| ID of a system account. For details, see [getCreatedOsAccountsCount](js-apis-osAccount.md#getosaccountlocalidfromprocess).|
| options | [StartOptions](js-apis-application-startOptions.md) | No| Parameters used for starting the ability.|

**Error codes**

| ID| Error Message|
| ------- | -------------------------------- |
| 401 | If the input parameter is not valid parameter. |

For details about the error codes, see [Ability Error Codes](../errorcodes/errorcode-ability.md).

**Example**

  ```ts
  var want = {
    deviceId: "",
    bundleName: "com.example.myapplication",
    abilityName: "EntryAbility"
  };
  var accountId = 100;
  var options = {
    windowMode: 0
  };

  try {
    this.context.startAbilityWithAccount(want, accountId, options)
      .then((data) => {
        // Carry out normal service processing.
        console.log('startAbilityWithAccount succeed');
      })
      .catch((error) => {
        // Process service logic errors.
        console.log('startAbilityWithAccount failed, error.code: ' + JSON.stringify(error.code) +
          ' error.message: ' + JSON.stringify(error.message));
      });
  } catch (paramError) {
    // Process input parameter errors.
    console.log('error.code: ' + JSON.stringify(paramError.code) +
      ' error.message: ' + JSON.stringify(paramError.message));
  }
  ```

## AbilityContext.setMissionLabel

setMissionLabel(label: string, callback:AsyncCallback&lt;void&gt;): void;

Sets a label for this ability in the mission. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| label | string | Yes| Label of the ability to set.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback used to return the result.|

**Example**

  ```ts
  this.context.setMissionLabel("test",(result) => {
      console.log('setMissionLabel result:' + JSON.stringify(result));
  });
  ```


## AbilityContext.setMissionLabel

setMissionLabel(label: string): Promise&lt;void&gt;;

Sets a label for this ability in the mission. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| label | string | Yes| Label of the ability to set.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

**Example**

  ```ts
  this.context.setMissionLabel("test").then(() => {
      console.log('success');
  }).catch((error) => {
      console.log('failed:' + JSON.stringify(error));
  });
  ```
## AbilityContext.setMissionIcon

setMissionIcon(icon: image.PixelMap, callback:AsyncCallback\<void>): void;

Sets an icon for this ability in the mission. This API uses an asynchronous callback to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| icon | [image.PixelMap](js-apis-image.md#pixelmap7) | Yes| Icon of the ability to set.|
| callback | AsyncCallback\<void> | Yes| Callback used to return the result.|

**Example**

  ```ts
    import image from '@ohos.multimedia.image';
    var imagePixelMap;
    var color = new ArrayBuffer(0);
    var initializationOptions = {
       size: {
           height: 100,
           width: 100
       }
    };
    image.createPixelMap(color, initializationOptions)
       .then((data) => {
           imagePixelMap = data;
       })
       .catch((err) => {
           console.log('--------- createPixelMap fail, err: ---------', err)
       });
    this.context.setMissionIcon(imagePixelMap, (err) => {
       console.log('---------- setMissionIcon fail, err: -----------', err);
    })
  ```


## AbilityContext.setMissionIcon

setMissionIcon(icon: image.PixelMap): Promise\<void>;

Sets an icon for this ability in the mission. This API uses a promise to return the result.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| icon | [image.PixelMap](js-apis-image.md#pixelmap7) | Yes| Icon of the ability to set.|

**Return value**

| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|

**Example**

  ```ts
    import image from '@ohos.multimedia.image';
    var imagePixelMap;
    var color = new ArrayBuffer(0);
    var initializationOptions = {
      size: {
          height: 100,
          width: 100
      }
    };
    image.createPixelMap(color, initializationOptions)
      .then((data) => {
          imagePixelMap = data;
      })
      .catch((err) => {
          console.log('--------- createPixelMap fail, err: ---------', err)
      });
    this.context.setMissionIcon(imagePixelMap)
      .then(() => {
          console.log('-------------- setMissionIcon success -------------');
      })
      .catch((err) => {
          console.log('-------------- setMissionIcon fail, err: -------------', err);
      });
  ```
## AbilityContext.restoreWindowStage

restoreWindowStage(localStorage: LocalStorage) : void;

Restores the window stage data for this ability.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Parameters**

| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| localStorage | LocalStorage | Yes| Storage used to store the restored window stage.|

**Example**

  ```ts
    var storage = new LocalStorage();
    this.context.restoreWindowStage(storage);
  ```

## AbilityContext.isTerminating

isTerminating(): boolean;

Checks whether this ability is in the terminating state.

**System capability**: SystemCapability.Ability.AbilityRuntime.Core

**Return value**

| Type| Description|
| -------- | -------- |
| boolean| The value **true** means that the ability is in the terminating state, and **false** means the opposite.|

**Example**

  ```ts
  var isTerminating = this.context.isTerminating();
  console.log('ability state :' + isTerminating);
  ```