Flutter app wont ask for Storage permission in release mode

Question

I'm using permission_handler package to ask for read permissions for storage in my app everything is working fine in debug mode and when i run my code with "flutter run --release" but the problem arises when i export my code as an apk the permissions dialog doesn't appear. i have no idea what I'm doing wrong here please help me out!!

here is the androidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.edithautotech.edithdisplayrelease">
    <!-- io.flutter.app.FlutterApplication is an android.app.Application that
         calls FlutterMain.startInitialization(this); in its onCreate method.
         In most cases you can leave this as-is, but you if you want to provide
         additional functionality it is fine to subclass or reimplement
         FlutterApplication and put your custom class here. -->
    
    <!-- Permissions options for the 'storage' group-->
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="com.android.vending.BILLING" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    
    <application
        android:name="io.flutter.app.FlutterApplication"
        android:label="Edith Display"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <!-- Displays an Android View that continues showing the launch screen
                 Drawable until Flutter paints its first frame, then this splash
                 screen fades out. A splash screen is useful to avoid any visual
                 gap between the end of Android's launch screen and the painting of
                 Flutter's first frame. -->
            <meta-data
              android:name="io.flutter.embedding.android.SplashScreenDrawable"
              android:resource="@drawable/launch_background"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
</manifest>

here is the dart code

import 'package:fluttertoast/fluttertoast.dart';
import 'package:permission_handler/permission_handler.dart';

class HomeScreen extends StatefulWidget {
  static const routeName = "/gallery";
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen>
    with SingleTickerProviderStateMixin {
  PermissionStatus _storageStatus = PermissionStatus.restricted;

  @override
  void initState() {
    super.initState();
    _initPermission();
  }

  void _initPermission() async {
    final PermissionStatus status = await _permission.request();
    setState(() {
      _storageStatus = status;
    });
  }
  void _checkPermission({Function handler}) async {
    switch (_storageStatus) {
      case PermissionStatus.granted:
        handler();
        break;
      case PermissionStatus.denied:
         Fluttertoast.showToast(msg: "Storage permission denied");
        break;
      case PermissionStatus.restricted:
         Fluttertoast.showToast(msg: "Storage permission restricted");
        break;
      case PermissionStatus.permanentlyDenied:
         Fluttertoast.showToast(msg: "Storage permission permanently denied");
        break;
      case PermissionStatus.undetermined:
         Fluttertoast.showToast(msg: "Storage permission undermined");
        break;
    }
    }
Void onUploadButtonClick(){
// showing media from device here
}

  @override
  Widget build(BuildContext context) {
    final ThemeData theme = Theme.of(context);
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.restaurantName,
          style: theme.appBarTheme.textTheme.headline1,
        ),),
      body: Container(color: Colors.Green),
floatingActionButton: FloatingActionButton.extended(
              onPressed: () {
                Fluttertoast.showToast(msg: "Upload Pressed");
                _checkPermission(
                  handler: () =>
                      onUploadButtonClick(context, user: widget.user),
                );
              },
              label: Text(
                'Upload',
                style: theme.textTheme.button,
              ),
              icon: Icon(
                Icons.cloud_upload,
                size: 30,
              ),
            )
          );
  }

}

Answer 1

I'm pretty sure I figured out this problem: https://stackoverflow.com/a/64235930/2025941

I solved it with a couple different ways:

1. Add proguard-rules.pro to android/app/proguard-rules.pro

#Flutter Wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }
-keep class androidx.lifecycle.** { *; } #https://github.com/flutter/flutter/issues/58479
#https://medium.com/@swav.kulinski/flutter-and-android-obfuscation-8768ac544421

2. add proguard to buildTypes in app level build.gradle

buildTypes {
    release {
        profile {
            matchingFallbacks = ['debug', 'release']
        }
    minifyEnabled true
    useProguard true
    proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    signingConfig signingConfigs.release
    }
}
lintOptions {
    disable 'InvalidPackage'
    checkReleaseBuilds false
}

3. You can also try running master channel in terminal:

flutter channel master

4. I also migrated android to AndroidX in Android Studio by navigating to SDK manager->SDK tools->checking and downloading Google Play services

5. I also made sure that compile SDK and target SDK is 29; there are issues with permission_handler package with SDK 30 at the moment.

6. I also edited the kotlin main activity file:

package yourpackage
import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() {
    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        GeneratedPluginRegistrant.registerWith(flutterEngine);
    }
}