为什么 Flutter App 降级会导致数据丢失？

如何解决为什么 Flutter App 降级会导致数据丢失？

问题：

我有一个使用 sembast 和 shared_preferences 来存储数据的应用。

最近我不小心降级了我的应用，导致它丢失了所有存储的数据。

我在物理设备和模拟器设备上对其进行了测试，两者都导致了相同的问题。 有没有办法解决这个问题？

注意：“修复这个”是指在降级的情况下防止进一步的数据丢失，而不是恢复丢失的数据）

重现步骤：

1)创建项目

2) 在共享引用或 sembast 中存储数据

3)热重启

4) 将版本号更改为比之前版本号更低的编号（例如：1.0.0+110 到 1.0.0+109）

5)热重启

Pubspec.yaml

version: 1.0.0+111

environment:
  sdk: ">=2.9.0 <3.0.0"

dependencies:
  Flutter:
    sdk: Flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.3
  excel: ^2.0.0-null-safety-3
  shared_preferences: ^2.0.6
  permission_handler: ^8.1.1
  path_provider: ^2.0.2
  sembast: ^3.1.0+2
  sembast_web: ^2.0.0+2 #remove web version not being used
  intl: ^0.17.0
  provider: ^5.0.0
  firebase_core: ^1.3.0
  firebase_analytics: ^8.1.2
  firebase_performance: ^0.7.0+5
  firebase_crashlytics: ^2.0.6
  firebase_auth: ^1.4.1
  get_it: ^7.1.3
  open_file: ^3.2.1
  Flutter_bloc: ^7.0.1
  cloud_firestore: ^2.2.2 #remove and maybe use cloud functions
  syncfusion_Flutter_charts: ^19.1.69+1
  url_launcher: ^6.0.3
  file_picker: ^3.0.3
  Flutter_typeahead: ^3.1.3
  purchases_Flutter: ^3.3.0
  device_info_plus: ^2.0.1

颤振医生：

[√] Flutter (Channel stable,2.2.2,on Microsoft Windows [Version 10.0.19043.1081],locale en-IN)
    • Flutter version 2.2.2 at D:\Applications\Flutter
    • Framework revision d79295af24 (2 weeks ago),2021-06-11 08:56:01 -0700
    • Engine revision 91c9fc8fe0
    • Dart version 2.13.3

[√] Android toolchain - develop for Android devices (Android SDK version 31.0.0-rc1)
    • Android SDK at D:\Applications\Android-SDK
    • Platform android-S,build-tools 31.0.0-rc1
    • Java binary at: D:\Applications\Android_studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6842174)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 4.1.0)
    • Android Studio at D:\Applications\Android_studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-Flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.8+10-b944.6842174)

[√] Connected device (3 available)
    • sdk gphone x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
    • Chrome (web)            • chrome        • web-javascript • Google Chrome 91.0.4472.114
    • Edge (web)              • edge          • web-javascript • Microsoft Edge 91.0.864.37

• No issues found!