Flutter权限处理程序包在权限被永久拒绝时无法打开应用程序设置。

Question

我已经在permission_handler软件包上工作了一段时间。尝试找出当用户永久拒绝应用程序访问权限时，iOS或Android的应用程序设置页面。

我的应用程序首先需要访问媒体库和相机。有经验的Flutter开发人员请尽可能详细地解释。我是Flutter开发的新手，也是整个移动应用程序开发的新手。

这是iOS上的podfile：

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
    target.build_configurations.each do |config|
            config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= [
               '$(inherited)',

               ## dart: PermissionGroup.calendar
               'PERMISSION_EVENTS=0',

               ## dart: PermissionGroup.reminders
               'PERMISSION_REMINDERS=0',

               ## dart: PermissionGroup.contacts
               # 'PERMISSION_CONTACTS=0',

               ## dart: PermissionGroup.camera
               # 'PERMISSION_CAMERA=1',

               ## dart: PermissionGroup.microphone
               # 'PERMISSION_MICROPHONE=0',

               ## dart: PermissionGroup.speech
               'PERMISSION_SPEECH_RECOGNIZER=0',

               ## dart: PermissionGroup.photos
               # 'PERMISSION_PHOTOS=1',

               ## dart: [PermissionGroup.location, PermissionGroup.locationAlways, PermissionGroup.locationWhenInUse]
               'PERMISSION_LOCATION=0',

               ## dart: PermissionGroup.notification
               # 'PERMISSION_NOTIFICATIONS=0',

               ## dart: PermissionGroup.mediaLibrary
               # 'PERMISSION_MEDIA_LIBRARY=1',

               ## dart: PermissionGroup.sensors
                'PERMISSION_SENSORS=0'
             ]
    end
  end
end

这里是info.plist文件-

<key>NSPhotoLibraryUsageDescription</key>
    <string>This app requires access to your photo gallery to view or save images</string>
    <key>NSPhotoLibraryAddUsageDescription</key>
    <string></string>

这是我的实际代码，在按钮按下时，我正在检查是否有权限打开画廊。

TextButton.icon(
    icon: const Icon(
       Icons.photo_library_rounded,
          size: 50,
        ),
   label: const Text('Pick from gallery',
      style: TextStyle(fontSize: 20)),
    onPressed: () {
      PermissionService().openPhotoGallery();
     },
),

这是我的权限类。该应用程序不会打开应用程序设置，而是仅在iOS上加载设置。

import 'package:permission_handler/permission_handler.dart';

class PermissionService {

  openPhotoGallery() async {
    var galleryAccessStatus = await Permission.mediaLibrary.status;
    if(!galleryAccessStatus.isGranted) {
      var status = await Permission.mediaLibrary.request();
      if(status.isPermanentlyDenied) {
        await openAppSettings();
      }
    }
  }
}

在查看Zeeyans的答案后，添加以下代码片段。openAppSettings不会打开应用程序设置页面，而是会打开“设置”页面。

- Sumchans

Answer 1

将replace替换为galleryAccessStatus != PermissionStatus.granted， 并将status.isPermanentlyDenied替换为status != PermissionStatus.granted。

openPhotoGallery() async {
    var galleryAccessStatus = await Permission.mediaLibrary.status;

    if(galleryAccessStatus != PermissionStatus.granted) { //here
      var status = await Permission.mediaLibrary.request();

      if(status != PermissionStatus.granted) {  //here
        await openAppSettings();
      }
    }
  }

- Zeeshan Ayaz

---

问题在于openAppSettings()方法并没有打开应用程序设置，而是打开了iOS系统的设置页面。我已经在原帖中添加了更多的上下文信息。 - Sumchans

Answer 2

我相信这是我发现的最好的解决方案。这是我按钮的onPressed函数，用于打开应用程序设置。

onPressed: () async {
                      await openAppSettings();
                      BasicMessageChannel<String?> lifecycleChannel = SystemChannels.lifecycle;
                      lifecycleChannel.setMessageHandler((msg) async {
                        if (msg!.endsWith("resumed")) {
                          lifecycleChannel.setMessageHandler(null);
                          List permissionslist = [
                            await Permission.locationWhenInUse.isGranted,
                            await Permission.bluetoothConnect.isGranted,
                            await Permission.bluetoothScan.isGranted,
                            await Permission.storage.isGranted
                          ];
                          if (permissionslist.firstWhereOrNull((element) => element != true) ==
                              null) {
                            setState(() => arePermissionsGiven = true);
                          }
                          else {
                            setState(() => arePermissionsGiven = false);
                          }
                        }
                        return Future(() => null);
                      });
                    }

- Miro

Answer 3

如果没有任何帮助，请检查您的iOS设备是否总体上启用了位置服务。我花了大约4个小时才找到这个问题所在。

- R4dix