# Ability

> ![icon-note.gif](public_sys-resources/icon-note.gif) **说明：**
> 本模块首批接口从API version 9 开始支持。后续版本的新增接口，采用上角标单独标记接口的起始版本。


Ability模块，提供对Ability生命周期、上下文环境等调用管理。


## 导入模块

  
```
import Ability from '@ohos.application.Ability';
```

## 属性

**系统能力**：以下各项对应的系统能力均为SystemCapability.Ability.AbilityRuntime.AbilityCore

| 名称 | 参数类型 | 可读 | 可写 | 说明 | 
| -------- | -------- | -------- | -------- | -------- |
| context | [AbilityContext](js-apis-ability-context.md) | 是 | 否 | 上下文。 | 
| launchWant | [Want](js-apis-application-Want.md) | 是 | 否 | Ability启动时的参数。 | 
| lastRequestWant | [Want](js-apis-application-Want.md) | 是 | 否 | Ability最后请求时的参数。| 


## Ability.onCreate

onCreate(want: Want, param: AbilityConstant.LaunchParam): void;

Ability创建时回调，执行初始化业务逻辑操作。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | want | [Want](js-apis-application-Want.md) | 是 | 当前Ability的Want类型信息，包括ability名称、bundle名称等。 | 
  | param | AbilityConstant.LaunchParam | 是 | 创建 ability、上次异常退出的原因信息。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onCreate(want, param) {
          console.log('onCreate, want:' + want.abilityName);
      }
  }
  ```


## Ability.onWindowStageCreate

onWindowStageCreate(windowStage: window.WindowStage): void

当WindowStage创建后调用。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | windowStage | window.WindowStage | 是 | WindowStage相关信息。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onWindowStageCreate(windowStage) {
          console.log('onWindowStageCreate');
      }
  }
  ```


## Ability.onWindowStageDestroy

onWindowStageDestroy(): void

当WindowStage销毁后调用。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**示例：**
    
  ```js
  class myAbility extends Ability {
      onWindowStageDestroy() {
          console.log('onWindowStageDestroy');
      }
  }
  ```


## Ability.onWindowStageRestore

onWindowStageRestore(windowStage: window.WindowStage): void

当迁移多实例ability时，恢复WindowStage后调用。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | windowStage | window.WindowStage | 是 | WindowStage相关信息。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onWindowStageRestore(windowStage) {
          console.log('onWindowStageRestore');
      }
  }
  ```


## Ability.onDestroy

onDestroy(): void;

Ability生命周期回调，在销毁时回调，执行资源清理等操作。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**示例：**
    
  ```js
  class myAbility extends Ability {
      onDestroy() {
          console.log('onDestroy');
      }
  }
  ```


## Ability.onForeground

onForeground(): void;

Ability生命周期回调，当应用处于前台时触发。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**示例：**
    
  ```js
  class myAbility extends Ability {
      onForeground() {
          console.log('onForeground');
      }
  }
  ```


## Ability.onBackground

onBackground(): void;

Ability生命周期回调，当应用处于后台时触发。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**示例：**
    
  ```js
  class myAbility extends Ability {
      onBackground() {
          console.log('onBackground');
      }
  }
  ```


## Ability.onContinue

onContinue(wantParam : {[key: string]: any}): AbilityConstant.OnContinueResult;

当ability迁移准备迁移时触发，保存数据。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | wantParam | {[key: string]: any} | 是 | want相关参数。 | 

**返回值：**

  | 类型 | 说明 | 
  | -------- | -------- |
  | AbilityConstant.OnContinueResult | 继续的结果。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onContinue(wantParams) {
          console.log('onContinue');
          wantParams["myData"] = "my1234567";
          return true;
      }
  }
  ```


## Ability.onNewWant

onNewWant(want: Want): void;

当ability的启动模式设置为单例时回调会被调用。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | want | [Want](js-apis-application-Want.md) | 是 | Want类型参数，如ability名称，包名等。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onNewWant(want) {
          console.log('onNewWant, want:' + want.abilityName);
      }
  }
  ```


## Ability.onConfigurationUpdated

onConfigurationUpdated(config: Configuration): void;

当系统配置更新时调用。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | config | [Configuration](js-apis-configuration.md) | 是 | 表示需要更新的配置信息。 | 

**示例：**
    
  ```js
  class myAbility extends Ability {
      onConfigurationUpdated(config) {
          console.log('onConfigurationUpdated, config:' + JSON.stringify(config));
      }
  }
  ```


## Caller

通用组件Caller通信客户端调用接口, 用来向通用组件服务端发送约定数据。


## Caller.call

call(method: string, data: rpc.Sequenceable): Promise<void>;

向通用组件服务端发送约定序列化数据。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | method | string | 是 | 约定的服务端注册事件字符串。 | 
  | data | rpc.Sequenceable | 是 | 由开发者实现的Sequenceable可序列化数据。 | 

**返回值：**

  | 类型 | 说明 | 
  | -------- | -------- |
  | Promise<void> | Promise形式返回应答。 | 

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  class MyMessageAble{ // 自定义的Sequenceable数据结构
      constructor(name, str) {
        this.name = name;
        this.str = str;
      }
      marshalling(messageParcel) {
          messageParcel.writeInt(this.num);
          messageParcel.writeString(this.str);
          console.log('MyMessageAble marshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
      unmarshalling(messageParcel) {
          this.num = messageParcel.readInt();
          this.str = messageParcel.readString();
          console.log('MyMessageAble unmarshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
  };
  var method = 'call_Function'; // 约定的通知消息字符串
  var caller;
  export default class MainAbility extends Ability {
      onWindowStageCreate(windowStage) {
        this.context.startAbilityByCall({
            bundleName: "com.example.myservice",
            abilityName: "com.example.myservice.MainAbility",
            deviceId: ""
        }).then((obj) => {
            caller = obj;
            let msg = new MyMessageAble(1, "world"); // 参考Sequenceable数据定义
            caller.call(method, msg)
                .then(() => {
                    console.log('Caller call() called');
                }).catch((e) => {
                console.log('Caller call() catch error ' + e);
            });
            console.log('Caller GetCaller Get ' + caller);
        }).catch((e) => {
            console.log('Caller GetCaller error ' + e);
        });
      }
      
  }
  ```


## Caller.callWithResult

callWithResult(method: string, data: rpc.Sequenceable): Promise<rpc.MessageParcel>;

向通用组件服务端发送约定序列化数据, 并将服务端返回的约定序列化数据带回。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | method | string | 是 | 约定的服务端注册事件字符串。 | 
  | data | rpc.Sequenceable | 是 | 由开发者实现的Sequenceable可序列化数据。 | 

**返回值：**

  | 类型 | 说明 | 
  | -------- | -------- |
  | Promise<rpc.MessageParcel> | Promise形式返回通用组件服务端应答数据。 | 

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  class MyMessageAble{
      constructor(name, str) {
        this.name = name;
        this.str = str;
      }
      marshalling(messageParcel) {
          messageParcel.writeInt(this.num);
          messageParcel.writeString(this.str);
          console.log('MyMessageAble marshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
      unmarshalling(messageParcel) {
          this.num = messageParcel.readInt();
          this.str = messageParcel.readString();
          console.log('MyMessageAble unmarshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
  };
  var method = 'call_Function';
  var caller;
  export default class MainAbility extends Ability {
      onWindowStageCreate(windowStage) {
        this.context.startAbilityByCall({
            bundleName: "com.example.myservice",
            abilityName: "com.example.myservice.MainAbility",
            deviceId: ""
        }).then((obj) => {
            caller = obj;
            let msg = new MyMessageAble(1, "world");
            caller.callWithResult(method, msg)
                .then((data) => {
                    console.log('Caller callWithResult() called');
                    let retmsg = new MyMessageAble(0, "");
                    data.readSequenceable(retmsg);
                }).catch((e) => {
                console.log('Caller callWithResult() catch error ' + e);
            });
            console.log('Caller GetCaller Get ' + caller);
        }).catch((e) => {
            console.log('Caller GetCaller error ' + e);
        });
      }
  }
  ```


## Caller.release

release(): void;

主动释放通用组件服务端的通信接口。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  var caller;
  export default class MainAbility extends Ability {
      onWindowStageCreate(windowStage) {
        this.context.startAbilityByCall({
            bundleName: "com.example.myservice",
            abilityName: "com.example.myservice.MainAbility",
            deviceId: ""
        }).then((obj) => {
            caller = obj;
            try {
                caller.release();
            } catch (e) {
                console.log('Caller Release error ' + e);
            }
            console.log('Caller GetCaller Get ' + caller);
        }).catch((e) => {
            console.log('Caller GetCaller error ' + e);
        });
      }
  }
  ```


## Caller.onRelease

onRelease(callback: OnReleaseCallBack): void;

注册通用组件服务端Stub断开监听通知。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | callback | OnReleaseCallBack | 是 | 返回onRelease回调结果。 | 

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  var caller;
  export default class MainAbility extends Ability {
      onWindowStageCreate(windowStage) {
        this.context.startAbilityByCall({
            bundleName: "com.example.myservice",
            abilityName: "com.example.myservice.MainAbility",
            deviceId: ""
        }).then((obj) => {
            caller = obj;
            try {
                caller.onRelease((str) => {
                    console.log(' Caller OnRelease CallBack is called ' + str);
                });
            } catch (e) {
                console.log('Caller Release error ' + e);
            }
            console.log('Caller GetCaller Get ' + caller);
        }).catch((e) => {
            console.log('Caller GetCaller error ' + e);
        });
      }
  }
  ```


## Callee

通用组件服务端注册和解除客户端caller通知送信的callback接口。


## Callee.on

on(method: string, callback: CaleeCallBack): void;

通用组件服务端注册消息通知callback。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | method | string | 是 | 与客户端约定的通知消息字符串。 | 
  | callback | CaleeCallBack | 是 | 一个rpc.MessageParcel类型入参的js通知同步回调函数, 回调函数至少要返回一个空的rpc.Sequenceable数据对象, 其他视为函数执行错误。 | 

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  class MyMessageAble{
      constructor(name, str) {
        this.name = name;
        this.str = str;
      }
      marshalling(messageParcel) {
          messageParcel.writeInt(this.num);
          messageParcel.writeString(this.str);
          console.log('MyMessageAble marshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
      unmarshalling(messageParcel) {
          this.num = messageParcel.readInt();
          this.str = messageParcel.readString();
          console.log('MyMessageAble unmarshalling num[' + this.num + '] str[' + this.str + ']');
          return true;
      }
  };
  var method = 'call_Function';
  function funcCallBack(pdata) {
      console.log('Callee funcCallBack is called ' + pdata);
      let msg = new MyMessageAble(0, "");
      pdata.readSequenceable(msg);
      return new MyMessageAble(10, "Callee test");
  }
  export default class MainAbility extends Ability {
      onCreate(want, launchParam) {
          console.log('Callee onCreate is called');
          this.callee.on(method, funcCallBack);
      }
  }
  ```


## Callee.off

off(method: string): void;

解除通用组件服务端注册消息通知callback。

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

**参数：**

  | 参数名 | 类型 | 必填 | 说明 | 
  | -------- | -------- | -------- | -------- |
  | method | string | 是 | 已注册的通知事件字符串。 | 

**示例：**
    
  ```js
  import Ability from '@ohos.application.Ability';
  var method = 'call_Function';
  export default class MainAbility extends Ability {
      onCreate(want, launchParam) {
          console.log('Callee onCreate is called');
          this.callee.off(method);
      }
  }
  ```

## OnReleaseCallBack

(msg: string): void;

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

| 名称 | 参数类型 | 可读 | 可写 | 说明 | 
| -------- | -------- | -------- | -------- | -------- |
| (msg: string) | function | 是 | 否 | 调用者注册的侦听器函数接口的原型。 | 
 

 ## CaleeCallBack

(indata: rpc.MessageParcel): rpc.Sequenceable;

**系统能力**：SystemCapability.Ability.AbilityRuntime.AbilityCore

| 名称 | 参数类型 | 可读 | 可写 | 说明 | 
| -------- | -------- | -------- | -------- | -------- |
| (indata: rpc.MessageParcel) | rpc.Sequenceable | 是 | 否 | 被调用方注册的消息侦听器函数接口的原型。 |