android - 创建自定义 ActivityResultContract 以请求位置权限

Question

我想创建一个自定义 ActivityResultContract 来请求具有自定义响应的粗略和精细位置。

class LocationPermission : ActivityResultContract<Void?, LocationPermissionResult>() {
   override fun createIntent(context: Context, input: Array<String>): Intent {
      val requestPermissions = arrayOf(
         Manifest.permission.ACCESS_FINE_LOCATION,
         Manifest.permission.ACCESS_COARSE_LOCATION
      )

      return Intent(ActivityResultContracts.RequestMultiplePermissions.ACTION_REQUEST_PERMISSIONS)
         .putExtra(ActivityResultContracts.RequestMultiplePermissions.EXTRA_PERMISSIONS, requestPermissions)
   }

   ...
}

从 Activity 中调用它:

private val reportLocationIntent = registerForActivityResult(LocationPermission()) { result ->
}

...reportLocationIntent.launch()

然而，这样做时永远不会调用 createIntent。我做错了什么？

Answer 1

您的相关代码存在编译错误，但这种方法似乎有效。我真的不知道问题的“自定义响应”应该是什么，所以我根据您的问题创建了一个名为 class LocationPermissionResult(val granted: Boolean) 的类。它主要是从 ActivityResultContracts 的 RequestMultiplePermissions 编译而来。

在API 30和API 33模拟器上测试，权限对话框打开，返回结果也是正确的。 (确保权限已添加到 AndroidManifest.xml)

这是源代码:

class LocationPermission : ActivityResultContract<Void?, LocationPermissionResult>() {

    private val permissions = arrayOf(
        Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION
    )

    override fun createIntent(context: Context, input: Void?): Intent {
        return Intent(ActivityResultContracts.RequestMultiplePermissions.ACTION_REQUEST_PERMISSIONS).putExtra(
            ActivityResultContracts.RequestMultiplePermissions.EXTRA_PERMISSIONS, permissions)
    }

    override fun getSynchronousResult(context: Context,
        input: Void?): SynchronousResult<LocationPermissionResult>? {
        val allGranted = permissions.all { permission ->
            ContextCompat.checkSelfPermission(
                context,
                permission
            ) == PackageManager.PERMISSION_GRANTED
        }
        return if (allGranted) {
            SynchronousResult(LocationPermissionResult(true))
        } else null
    }

    override fun parseResult(resultCode: Int, intent: Intent?): LocationPermissionResult {
        if (resultCode != Activity.RESULT_OK) return LocationPermissionResult(false)
        if (intent == null) return LocationPermissionResult(false)
        val grantResults = intent.getIntArrayExtra(
            ActivityResultContracts.RequestMultiplePermissions.EXTRA_PERMISSION_GRANT_RESULTS)
        return LocationPermissionResult(grantResults?.all { it == PackageManager.PERMISSION_GRANTED } == true)
    }
}

class LocationPermissionResult(val granted: Boolean)