What are the differences between the UIAbility and UIExtensionAbility? What are their use scenarios?

The UIAbility is used to implement independent UIs, and the UIExtensionAbility is used for functional extensions.

The UIAbility includes UI components that allow for user interaction. When a UIAbility is running, its corresponding task view is displayed in the task list. It is recommended that the UIAbility be used in the main page, video playback page, and settings page.

import { UIAbility } from "@kit.AbilityKit";
import { window } from "@kit.ArkUI";

// MainAbility.ets
export default class MainAbility extends UIAbility {
  onWindowStageCreate(windowStage: window.WindowStage) {
    windowStage.loadContent('pages/MainPage', (err) => {
      if (err) {
        console.error('Page loading failed');
      }
    });
  }
}

The UIExtensionAbility is an ExtensionAbility component with a UI. When running, it does not have an independent window but is embedded as a node in the host window and displayed within it. It also does not have a corresponding task view in the task list. It is recommended that the UIExtensionAbility be used in scenarios such as floating windows and shortcut menus.
```
import { UIExtensionAbility, AbilityConstant } from '@kit.AbilityKit';

export default class UIExtAbility extends UIExtensionAbility {
  onCreate(launchParam: AbilityConstant.LaunchParam) {
    console.log(`onCreate, launchParam: ${JSON.stringify(launchParam)}`);
  }
}
```

Reference

UIAbility Overview

目录

What are the differences between the UIAbility and UIExtensionAbility? What are their use scenarios?