!21021 [翻译完成】#I7HMW7

Merge pull request !21021 from Annie_wang/PR18302

en/application-dev/application-models/driverextensionability.md

+# DriverExtensionAbility
+
+[DriverExtensionAbility](../reference/apis/js-apis-app-ability-driverExtensionAbility.md) is an ExtensionAbility of the driver type that provides driver-related extension framework. If the capabilities of a device can be expanded by inserting an external hardware module, you can install the driver of the hardware module through an application. DriverExtensionAbility can be used to develop such applications.
+
+
+The [DriverExtensionAbility](../reference/apis/js-apis-app-ability-driverExtensionAbility.md) can be bound to an application through the DriverExtensionManager and process related transactions in the background based on the application request information.
+Each type of ExtensionAbility has its own context. The DriverExtensionAbility provides related capabilities through the [DriverExtensionContext](../reference/apis/js-apis-inner-application-driverExtensionContext.md).
+         
+This topic describes how to use DriverExtensionAbility in the following scenarios:
+
+- [DriverExtensionAbility](#driverextensionability)
+  - [How to Develop](#how-to-develop)
+
+## How to Develop
+
+To implement a driver, create a DriverExtensionAbility in the DevEco Studio project. The procedure is as follows:
+
+1. In the **ets** directory of a module in the project, right-click and choose **New > Directory** to create a directory named **driverextability**.
+
+2. In the **driverextability** directory, right-click and choose **New > TypeScript File** to create a file named **DriverExtAbility.ts**.
+
+3. Open the **DriverExtAbility.ts** file, import the [RPC module](../reference/apis/js-apis-rpc.md), and overload the **onRemoteMessageRequest()** method to receive messages from the application and return the processing result to the application. **REQUEST_VALUE** is used to verify the service request code sent by the application.
+   
+   ```ts
+   import rpc from '@ohos.rpc';
+   
+   const REQUEST_CODE = 99;
+   
+   class StubTest extends rpc.RemoteObject {
+     constructor(des) {
+       super(des);
+     }
+     
+     // Receive the message sent from the application and return the processing result to the application.
+     onRemoteMessageRequest(code, data, reply, option) {
+       if (code === REQUEST_CODE) {
+         // Receive the data sent from the application.
+         // When the application calls data.writeInt() multiple times to write data, the driver can receive the corresponding data by calling data.readInt() for multiple times.
+         let optFir = data.readInt();
+         let optSec = data.readInt();
+         // The driver returns the data processing result to the application.
+         // In the example, two pieces of data are received, and the sum of the two pieces of data is returned to the application.
+         reply.writeInt(optFir + optSec);
+       }
+       return true;
+     }
+   }
+   ```
+
+
+4. In the **DriverExtAbility.ts** file, import the dependency package [DriverExtensionAbility](../reference/apis/js-apis-app-ability-driverExtensionAbility.md), which provides the **onInit()**, **onRelease()**, **onConnect()**, and **onDisconnect()** lifecycle callbacks. Then, customize a class to inherit from [DriverExtensionAbility](../reference/apis/js-apis-app-ability-driverExtensionAbility.md) and override the lifecycle callbacks as required.
+   
+   ```ts
+   import DriverExtensionAbility from '@ohos.app.ability.DriverExtensionAbility';
+   import rpc from '@ohos.rpc';
+   
+   const TAG: string = '[Example].[Entry].[DriverExtAbility]';
+   const REQUEST_CODE = 99;
+   
+   class StubTest extends rpc.RemoteObject {
+     // ...
+   }
+   
+   export default class DriverExtAbility extends DriverExtensionAbility {
+     onInit(want) {
+       console.info(TAG, `onInit, want: ${want.abilityName}`);
+     }
+   
+     onRelease() {
+       console.info(TAG, `onRelease, want: ${want.abilityName}`);
+     }
+   
+     onConnect(want) {
+       console.info(TAG, `onConnect, want: ${want.abilityName}`);
+       return new StubTest("test");
+     }
+   
+     onDisconnect(want) {
+       console.info(TAG, `onDisconnect, want: ${want.abilityName}`);
+     }
+   
+     onDump() {
+       console.info(TAG, `onDump, params:` + JSON.stringify(params));
+       return ['params'];
+     }
+   }
+   ```
+
+5. Register the DriverExtensionAbility in the [**module.json5** file](../quick-start/module-configuration-file.md) of the module in the project. Set **type** to **service** and **srcEntry** to the code path of the DriverExtensionAbility component.
+   
+   ```json
+   {
+     "module": {
+       // ...
+       "extensionAbilities": [
+         {
+           "name": "DriverExtAbility",
+           "icon": "$media:icon",
+           "description": "driver",
+           "type": "driver",
+           "exported": true,
+           "srcEntry": "./ets/driverextability/DriverExtAbility.ts",
+           "metadata": [
+            {
+              "name": "bus", // The bus is mandatory.
+              "value": "USB",
+            },
+            {
+              "name": "desc", // Description of the driver, which is mandatory.
+              "value": "the sample of driverExtensionAbility",
+            },
+            {
+              "name": "vendor", // Driver vendor name, which is mandatory.
+              "value": "string",
+            },
+            {
+              "name": "vid", // List of supported USB vendor IDs, separated by commas (,). The value cannot be empty.
+              "value": "string, string",
+            },
+            {
+              "name": "pid", // List of supported USB product IDs, separated by commas (,). The value cannot be empty.
+              "value": "string, string",
+            }
+           ]
+         }
+       ]
+     }
+   }
+   ```

en/application-dev/reference/apis/js-apis-app-ability-driverExtensionAbility.md

+# @ohos.app.ability.DriverExtensionAbility (DriverExtensionAbility)
+
+The **DriverExtensionAbility** module provides the ExtensionAbility related to drivers. It provides lifecycle callbacks to be invoked when a driver is created, destroyed, connected, or disconnected.
+
+> **NOTE**
+> 
+> The initial APIs of this module are supported since API version 10. 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.
+
+## Modules to Import
+
+```ts
+import DriverExtension from '@ohos.app.ability.DriverExtensionAbility';
+```
+
+## Required Permissions
+
+None.
+
+## Attributes
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+| Name| Type| Readable| Writable| Description|
+| -------- | -------- | -------- | -------- | -------- |
+| context | [DriverExtensionContext](js-apis-inner-application-driverExtensionContext.md)  | Yes| No| Context of the **DriverExtension**. This context is inherited from **ExtensionContext**.|
+
+
+## DriverExtensionAbility.onInit
+
+onInit(want: Want): void;
+
+Called when a DriverExtensionAbility is created to initialize the service logic.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| want |  [Want](js-apis-app-ability-want.md) | Yes| Want information related to this DriverExtensionAbility, including the ability name and bundle name.|
+
+**Example**
+
+  ```ts
+  class DriverExt extends DriverExtension {
+    onInit(want) {
+      console.log('onInit, want: ${want.abilityName}');
+    }
+  }
+  ```
+
+
+## DriverExtensionAbility.onRelease
+
+onRelease(): void;
+
+Called when this DriverExtensionAbility is destroyed to clear resources.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+**Example**
+
+  ```ts
+  class DriverExt extends DriverExtension {
+    onRelease() {
+      console.log('onRelease');
+    }
+  }
+  ```
+
+
+## DriverExtensionAbility.onConnect
+
+onConnect(want: Want): rpc.RemoteObject | Promise<rpc.RemoteObject>;
+
+Called following **onCreate()** when a DriverExtensionAbility is started by calling **connectAbility()**. A **RemoteObject** object is returned for communication between the server and client.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| want |  [Want](js-apis-app-ability-want.md)| Yes| Want information related to this DriverExtensionAbility, including the ability name and bundle name.|
+
+**Return value**
+
+| Type| Description|
+| -------- | -------- |
+| rpc.RemoteObject | A **RemoteObject** object used for communication between the server and client.|
+
+**Example**
+
+  ```ts
+  import rpc from '@ohos.rpc';
+  class StubTest extends rpc.RemoteObject{
+      constructor(des) {
+          super(des);
+      }
+      onRemoteRequest(code, data, reply, option) {
+      }
+  }
+  class DriverExt extends DriverExtension {
+    onConnect(want) {
+      console.log('onConnect , want: ${want.abilityName}');
+      return new StubTest('test');
+    }
+  }
+  ```
+
+If the returned **RemoteObject** object depends on an asynchronous API, you can use the asynchronous lifecycle.
+
+  ```ts
+import rpc from '@ohos.rpc';
+class StubTest extends rpc.RemoteObject{
+    constructor(des) {
+        super(des);
+    }
+    onRemoteRequest(code, data, reply, option) {
+    }
+}
+async function getDescriptor() {
+    // Call the asynchronous function.
+    return "asyncTest"
+}
+class DriverExt extends DriverExtension {
+  async onConnect(want) {
+    console.log(`onConnect , want: ${want.abilityName}`);
+    let descriptor = await getDescriptor();
+    return new StubTest(descriptor);
+  }
+}
+  ```
+
+## DriverExtensionAbility.onDisconnect
+
+onDisconnect(want: Want): void | Promise\<void>;
+
+Called when a client is disconnected from this DriverExtensionAbility.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| want |[Want](js-apis-app-ability-want.md)| Yes| Want information related to this DriverExtensionAbility, including the ability name and bundle name.|
+
+**Example**
+
+  ```ts
+  class DriverExt extends DriverExtension {
+    onDisconnect(want) {
+      console.log('onDisconnect, want: ${want.abilityName}');
+    }
+  }
+  ```
+
+After the **onDisconnect** lifecycle callback is executed, the application may exit. As a result, the asynchronous function in **onDisconnect** may fail to be executed correctly, for example, asynchronously writing data to the database. The asynchronous lifecycle can be used to ensure that the subsequent lifecycle continues after the asynchronous **onDisconnect** is complete.
+
+  ```ts
+class DriverExt extends DriverExtension {
+  async onDisconnect(want) {
+    console.log('onDisconnect, want: ${want.abilityName}');
+    // Call the asynchronous function.
+  }
+}
+  ```
+
+
+## DriverExtensionAbility.onDump
+
+onDump(params: Array\<string>): Array\<string>;
+
+Dumps client information.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**System API**: This is a system API and cannot be called by third-party applications.
+
+**Parameters**
+
+| Name| Type| Mandatory| Description|
+| -------- | -------- | -------- | -------- |
+| params | Array\<string> | Yes| Parameters in the form of a command.|
+
+**Example**
+    
+  ```ts
+  class DriverExt extends DriverExtension {
+      onDump(params) {
+          console.log('dump, params: ${JSON.stringify(params)}');
+          return ['params'];
+      }
+  }
+  ```

en/application-dev/reference/apis/js-apis-inner-application-driverExtensionContext.md

+# DriverExtensionContext
+
+The **DriverExtensionContext** module provides the context of **DriverExtensionAbility**. It inherits from **ExtensionContext**.
+
+The **DriverExtensionContext** module provides the operations that need to be actively initiated in the **DriverExtensionAbility** implementation.
+
+> **NOTE**
+> 
+>  - The initial APIs of this module are supported since API version 10. 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.
+
+## Modules to Import
+
+```ts
+import common from '@ohos.app.ability.common';
+```
+
+## How to Use
+
+Before using **DriverExtensionContext**, you need to obtain it through a **DriverExtensionAbility** child class instance.
+
+```ts
+  import DriverExtensionAbility from '@ohos.app.ability.DriverExtensionAbility';
+
+  let context;
+  class EntryAbility extends DriverExtensionAbility {
+    onInit() {
+      context = this.context; // Obtain DriverExtensionContext.
+    }
+  }
+```
+
+## DriverExtensionContext.updateDriverState
+
+updateDriverState(): void;
+
+Updates the driver state. This interface is reserved and does not provide specific functionality currently.
+
+**System capability**: SystemCapability.Driver.ExternalDevice
+
+**Example**
+
+  ```ts
+  this.context.updateDriverState() ;
+  ```