如何在 Flutter 插件中请求权限？

Question

我正在尝试使用一个简单的 Flutter 插件（语音识别包装器），但不知道如何在 Android 23 或更高版本上请求适当的权限。在 Dart 部分我有：

  Future requestPermissions() => 
  _channel.invokeMethod("speech.requestPermissions");

在Android部分：

  public class SpeechRecognitionPlugin implements MethodCallHandler, RecognitionListener,
    PluginRegistry.RequestPermissionResultListener {

插件注册：

  public static void registerWith(Registrar registrar) {
    final MethodChannel channel = new MethodChannel(registrar.messenger(), "speech_recognition");
    SpeechRecognitionPlugin speechRecognitionPlugin = new 
    SpeechRecognitionPlugin(registrar.activity(), channel);
    channel.setMethodCallHandler(speechRecognitionPlugin);
    registrar.addRequestPermissionResultListener(speechRecognitionPlugin);
  }

方法调用：

else if (call.method.equals("speech.requestPermissions")) {
        Log.d(LOG_TAG, "speech.requestPermissions");
        if (ActivityCompat.shouldShowRequestPermissionRationale(activity,
                Manifest.permission.RECORD_AUDIO)) {
            Toast.makeText(activity.getApplicationContext(), "This application needs the Record Audio permission for recognition to work", Toast.LENGTH_LONG).show();
        } else {
            Log.d(LOG_TAG, "Requesting permissions");
            ActivityCompat.requestPermissions(activity,
                    new String[]{Manifest.permission.RECORD_AUDIO},
                    1);
        }
        result.success(hasRecordAudioPermission());

结果回调：

@Override                                                                                            
public boolean onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults) {
    boolean granted = false;
    switch (requestCode) {
        case 1: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                granted = true;
            }
            speechChannel.invokeMethod("speech.onPermission", granted);
            return true;
        }
    }
    return false;
}

从logcat我看到“speech.requestPermissions”调用发生了，但是没有显示标准的Android系统权限请求，只是logcat中的这个可能是相关的：

D/ViewRootImpl(21171): #1 mView = android.widget.LinearLayout{64f050b 
V.E...... ......I. 0,0-0,0 #102039d android:id/toast_layout_root}
D/ViewRootImpl(21171): MSG_RESIZED_REPORT: ci=Rect(0, 0 - 0, 0) vi=Rect(0, 0 - 0, 0) or=1
D/ViewRootImpl(21171): #3 mView = null

什么是请求 Flutter 插件权限的正确方法？

编辑：当对话框正确显示时，这不适用于第一次运行，但适用于用户最初未授予权限或通过设置撤销权限时的后续运行。我意识到这会显着改变问题（使其显示为边缘情况），但 Android 权限不应该以这种方式工作。

编辑：权限存在于 AndroidManifest.xml

Answer 1

假设您想使用permission_handler 包请求相机权限。

1. 在pubspec.yaml 文件中：

   permission_handler: ^8.0.0+2
   

2. (Android)添加android/app/src/main/AndroidManifest.xml文件的权限

   <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> 
     ...
    </manifest>
   

3. （对于 iOS），

   (i) 将此添加到您的 info.plist 文件中

   <key>NSCameraUsageDescription</key>
   <string>App needs camera permission to work</string>
   

   (ii) 将'PERMISSION_CAMERA=1' 添加到您的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)',
   
           ## Add the following line.
            'PERMISSION_CAMERA=1'
         ]
   
       end
     end
   end
   

4. 请求许可：

   final status = await Permission.camera.request();
   if (status == PermissionStatus.granted) {
     print('Permission granted');
   } else if (status == PermissionStatus.denied) {
     print('Permission denied. Show a dialog and again ask for the permission');
   } else if (status == PermissionStatus.permanentlyDenied) {
     print('Take the user to the settings page.');
     await openAppSettings();
   }
   

Answer 2

使用Permission plugin for flutter

请求许可

import 'package:permissions_plugin/permissions_plugin.dart';

Map<Permission, PermissionState> permission = await PermissionsPlugin
    .requestPermissions([
        Permission.ACCESS_FINE_LOCATION,
        Permission.ACCESS_COARSE_LOCATION,
        Permission.READ_PHONE_STATE
    ]);

检查状态权限

import 'package:permissions_plugin/permissions_plugin.dart';

Map<Permission, PermissionState> permission = await PermissionsPlugin
    .checkPermissions([
      Permission.ACCESS_FINE_LOCATION,
      Permission.ACCESS_COARSE_LOCATION,
      Permission.READ_PHONE_STATE
    ]);

Answer 3

我有这个为位置权限工作。我唯一不同的是在您的方法调用中：

ActivityCompat.requestPermissions(activity,
                new String[]{Manifest.permission.RECORD_AUDIO},
                1);

我没有使用“ActivityCompat”，而是将注册器存储在本地最终变量中，并且我正在执行以下操作：

registrar.activity().requestPermissions(activity,
                new String[]{Manifest.permission.RECORD_AUDIO},
                1);

编辑：还要确保您已在 AndroidManifest.xml 中包含相关权限

<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- Add this -->
    <uses-permission android:name="android.permission.RECORD_AUDIO" />

    <!-- Flutter stuff --->
</manifest>