如何检查用户是否已从android中的活动/片段外部授予权限

Question

我正在使用 dexter 为导航组件提供运行时权限。

我有一个包含多个片段的活动。

在活动中，我想请求用户授予权限（存储）。

然后我有一个类（不是 Activity 或 Fragment），需要在访问一些需要运行时权限的代码之前检查用户是否已授予权限..

我还有一个 viewModel 运行需要运行时权限的代码

问题

我无法在任何这些类/viewModel 中访问上下文。我现在如何检查用户是否已授予权限。

实用类

fun requestExternalStoragePermission(context: Context, callback: PermissionsCallback) {
    Dexter.withContext(context) //
        .withPermissions(listOf(Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE))
        .withListener(object : MultiplePermissionsListener {
            override fun onPermissionsChecked(p0: MultiplePermissionsReport?) {
                p0?.let {
                    if (p0.areAllPermissionsGranted()) {
                        callback.onPermissionRequest(granted = true)
                    } else {
                        callback.onPermissionRequest(granted = false)
                    }
                }
            }
            override fun onPermissionRationaleShouldBeShown(
                p0: MutableList<PermissionRequest>?,
                p1: PermissionToken?
            ) {
                p1?.continuePermissionRequest()
            }
        })
        .check()
}

界面

 interface PermissionsCallback {
  fun onPermissionRequest(granted: Boolean)
}

MainActivity

 override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    checkForPermission()
    setContentView(binding.root)
}

 private fun checkForPermission(){
  Utility.requestExternalStoragePermission(
      this,
      object : PermissionsCallback {
      override fun onPermissionRequest(granted: Boolean) {
      if (granted) {
       //good
       } else {
       //show settings
     }
}

更新

音乐服务

class MusicService : MediaBrowserServiceCompat() {

 private val serviceJob = Job()
 private val serviceScope = CoroutineScope(Dispatchers.Main + 
serviceJob)

var context: Context? = null
   
    override fun onCreate() {
    super.onCreate()
    context = this
    checkForPermission()
  
 }

  private fun checkForPermission(){
    Utility.requestExternalStoragePermission(
        this,
        object : PermissionsCallback {
            override fun onPermissionRequest(granted: Boolean) {
                if (granted) {
                    //good, load songs
                    serviceScope.launch {
                        musicSource.fetchMediaData()
                    }
                } else {
                    //do something else
                    Toast.makeText(context, "We need permission nowwww", Toast.LENGTH_LONG)
                        .show()
                }
            }
        })
 }

 override fun onDestroy() {
    super.onDestroy()
    serviceScope.cancel()

    exoPlayer.removeListener(musicPlayerEventListener)
    exoPlayer.release()

}

}

视图模型

 init {
    viewModelScope.launch {
        val allArtistes = artisteDatabase.getAllArtiste().....//I need to check here tooo
        _artisteList.value = Resource.success(allArtistes)
    }
}

fun doGetArtisteSongs(long: Long){
    viewModelScope.launch {
         val artisteSongs = artisteDatabase.getArtisteSongs(long).....//I need to check here too
        _artisteSongList.value = Resource.success(artisteSongs)
    }
}

我无法使用我的实用程序函数来检查该非活动/片段类和视图模型的权限，因为它需要一个“上下文”。

正确的出路是什么？

Answer 1

如果 MusicService 是服务类，您可以从服务中获取上下文。

 Context context;
    
    @Override
    public void onCreate() {
        super.onCreate();
        context = this;
    }
    
 //then you can call requestExternalStoragePermission() using context.

 //If you want context in viewmodel use HILT dependency injection library.

 @ViewModelInject
    public MainViewModel(MainRepository mainRepository, @ApplicationContext Context context) {
        this.repository = mainRepository;
        this.context = context;

    }