flutter pub add double_back_to_close_app根據套件公開資料產生的選型評估，僅供參考。
此 Flutter 套件允許 Android 使用者透過連續按兩次返回鍵來關閉應用程式，藉由防止意外退出來改善使用者體驗。它可在多個平台（包括 iOS、Web、macOS、Windows 及 Linux）上運作，提供一致的行為。該套件輕量且易於整合，設定簡單。它提供可自訂的返回鍵按壓間隔，並支援具原生功能的 Android 與 iOS 設備。
以下為關聯原始碼儲存庫的 README 原文快照，最新內容請造訪原始碼儲存庫。
A Flutter package that allows Android users to press the back-button twice to close the app.
Inside a Scaffold that wraps all your Widgets, place the DoubleBackToCloseApp passing a SnackBar:
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: DoubleBackToCloseApp(
child: Home(),
snackBar: const SnackBar(
content: Text('Tap back again to leave'),
),
),
),
);
}
}
I've implemented such solution when I answered this question in Stack Overflow, and since this feature seems to be implemented very often, I decided to extract it in a lightweight library.