!7144 翻译完成：6254 【元能力】新增应用上下文环境监听接口资料

Merge pull request !7144 from wusongqing/TR6254

en/application-dev/reference/apis/js-apis-application-EnvironmentCallback.md

+# EnvironmentCallback
+
+The **EnvironmentCallback** module provides the **onConfigurationUpdated** API for the application context to listen for system environment changes.
+
+> **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.
+
+
+## Modules to Import
+
+```js
+import EnvironmentCallback from "@ohos.application.EnvironmentCallback";
+```
+
+
+## EnvironmentCallback.onConfigurationUpdated
+
+onConfigurationUpdated(config: Configuration): void;
+
+Called when the system environment changes.
+
+**System capability**: SystemCapability.Ability.AbilityRuntime.AbilityCore
+
+**Parameters**
+
+  | Name| Type| Mandatory| Description| 
+  | -------- | -------- | -------- | -------- |
+  | config | [Configuration](js-apis-configuration.md) | Yes| **Configuration** object after the change.|
+
+**Example**
+    
+
+  ```js
+import AbilityStage from "@ohos.application.AbilityStage";
+
+var callbackId;
+
+export default class MyAbilityStage extends AbilityStage {
+    onCreate() {
+        console.log("MyAbilityStage onCreate")
+        globalThis.applicationContext = this.context.getApplicationContext();
+        let EnvironmentCallback  =  {
+            onConfigurationUpdated(config){
+                console.log("onConfigurationUpdated config:" + JSON.stringify(config));
+            },
+        }
+        // 1. Obtain an applicationContext object.
+        let applicationContext = globalThis.applicationContext;
+        // 2. Register a listener for the environment changes through the applicationContext object.
+        callbackId = applicationContext.registerEnvironmentCallback(EnvironmentCallback);
+        console.log("registerEnvironmentCallback number: " + JSON.stringify(callbackId));
+    }
+    onDestroy() {
+        let applicationContext = globalThis.applicationContext;
+        applicationContext.unregisterEnvironmentCallback(callbackId, (error, data) => {
+            console.log("unregisterEnvironmentCallback success, err: " + JSON.stringify(error));
+        });
+    }
+}
+  ```