Fix Flutter App Text Reverting After Relaunch

Are you experiencing a frustrating issue where your Flutter app’s text changes revert to an older version after you relaunch the app, even though you’ve updated the code? This article will guide you through the reasons why this happens and provide a practical solution.

Understanding Hot Reload vs. App Build

The core of the problem lies in the difference between Flutter’s hot reload feature and a full app build.

• Hot Reload: This is a fantastic feature that allows you to quickly see changes in your app by injecting updated code into the running application. It preserves the app’s state, making development faster. However, hot reload only updates the app state in memory and does not update the installed application package.
• App Build: This process creates a new version of your application package (APK for Android, IPA for iOS). When you build the app, the current state of your code is compiled and packaged into a fresh installable file.

Therefore, when you use hot reload to change the text to “Hello”, and then stop the app and relaunch, you are launching the old app package, which still contains the original text “This is my First App”.

The Solution: Rebuild Your Flutter App

To permanently update your Flutter app with the latest code changes, you need to rebuild the app. Here’s how:

1. Stop the Running App: Ensure the app is completely stopped in your IDE or on your device.
2. Rebuild the App: There are several ways to trigger a rebuild, depending on your IDE:
   • Visual Studio Code:
     • Use the “Run” -> “Start Debugging” option (or press F5). This usually performs a full build.
     • Alternatively, use the terminal and execute: flutter run (make sure you are in the root directory of your project)
   • Android Studio:
     • Use the “Build” -> “Build APK(s)” / “Build Bundle(s)” option.
     • Alternatively, use the terminal and execute: flutter run (make sure you are in the root directory of your project)
3. Install the New App Package: After the build process completes, you will have a new APK/IPA file. Uninstall the old version of the app from your device and install the new one. The new app should now display the updated text “Hello”.

Code Example

Here’s a simple Flutter code snippet illustrating the text change:

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('My First App'),
        ),
        body: Center(
          child: Text(
            'Hello', // Change this text
            style: TextStyle(fontSize: 24),
          ),
        ),
      ),
    );
  }
}

Possible Errors and Solutions

Sometimes, the build process can encounter errors. Here are a few common issues and their solutions:

• Gradle Build Failed (Android):
  • Error: Issues related to dependencies, SDK versions, or Gradle configuration.
  • Solution: Check your android/build.gradle and android/app/build.gradle files. Ensure your dependencies are up-to-date, your SDK versions are correctly configured, and your Gradle version is compatible. You might need to update your Gradle version in gradle-wrapper.properties file located in the android/gradle/wrapper directory. Try running “Flutter clean” in the terminal.
• CocoaPods Issues (iOS):
  • Error: Problems with pod dependencies or installation.
  • Solution: Navigate to your ios directory in the terminal and run pod install. If that doesn’t work, try pod update. If you still have issues, delete the Podfile.lock file and the Pods directory and try pod install again.
• Conflicting Dependencies:
  • Error: Multiple packages requiring different versions of the same dependency.
  • Solution: Use the flutter pub deps command in the terminal to analyze your dependencies. You might need to upgrade or downgrade some packages to resolve conflicts. Consult the package documentation for compatibility information.
• Version Compatibility Issues
  • Error: Problems with the Flutter version, Dart version, or the plugins versions.
  • Solution: Make sure to update your Flutter SDK to the latest stable version by running flutter upgrade command. Also, update Dart version to match with Flutter SDK version and check plugins’ dependencies for compatibility.

Conclusion

By understanding the difference between hot reload and a full app build, you can avoid the frustrating issue of text changes reverting after a relaunch. Remember to rebuild your app to ensure that your latest code changes are permanently reflected in the installed application package. Happy coding!