Flutter应用程序在发布模式下不会请求存储权限

Question

我正在使用permission_handler包请求对应用程序中存储的读取权限，在调试模式下一切工作正常，当我以“flutter run-release”运行代码时，问题就出现了，但当我将代码导出为apk时，权限对话框不会出现。我不知道我做错了什么请帮帮我！！

<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>

这是飞镖代码

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

我很确定我已经解决了这个问题:https://stackoverflow.com/A/64235930/2025941

我用了几种不同的方法来解决这个问题：

1. 将proguard-rules.pro添加到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

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
}

flutter channel master

我还确保编译SDK和目标SDK是29；目前SDK30中的permission_handler包存在问题。

我还编辑了kotlin主活动文件：

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);
    }
}