根据这个:http://developer.android.com/preview/features/runtime-permissions.html#coding一个应用程序可以检查运行时权限和请求权限，如果它还没有被授予。弹出如下对话框:
如果用户拒绝一个重要的权限，在我看来，应用程序应该显示一个解释为什么需要权限和什么影响拒绝。该对话框有两个选项:
重试(再次请求许可) 拒绝(应用程序将工作没有该许可)。
但是，如果用户选中“Never ask again”，则不应该显示带有解释的第二个对话框，特别是如果用户之前已经拒绝了一次。 现在的问题是:我的应用程序如何知道用户是否选中了Never ask again?IMO onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)没有给我这个信息。
第二个问题是:谷歌是否计划在权限对话框中包含一个自定义消息，以解释为什么应用程序需要权限?这样就不会出现第二个对话框，这肯定会带来更好的用户体验。
当前回答
OnRequestPermissionResult-free和shouldshowrequestpermissionrationalfree方法:
public static void requestDangerousPermission(AppCompatActivity activity, String permission) {
if (hasPermission(activity, permission)) return;
requestPermission();
new Handler().postDelayed(() -> {
if (activity.getLifecycle().getCurrentState() == Lifecycle.State.RESUMED) {
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
intent.setData(Uri.parse("package:" + context.getPackageName()));
context.startActivity(intent);
}
}, 250);
}
如果没有权限弹出，250ms后打开设备设置(如果选择了“Never ask again”，就是这种情况)。
其他回答
shouldShowRequestPermissionRationale根据之前权限请求中的用户首选项返回true或false。
如果用户只是拒绝权限(不是永远)shouldShowRequestPermissionRationale将返回true。如果永远拒绝许可，则返回false。窍门是即使用户允许了权限shouldShowRequestPermissionRationale也会返回false。
因此，我们可以结合这两个条件来得到永不再问的选择与否。
因此，如果用户不允许权限，并且shouldShowRequestPermissionRationale返回false，那么这意味着用户选择永远不会再次请求权限。
https://stackoverflow.com/a/58114769/5151336
这个示例演示了当用户选择“拒绝&不要再次询问”时如何处理
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
registerStoragePermission()
registerGalleryLauncher()
registerCameraPermission()
registerCameraLauncher()
}
private fun registerCameraPermission() {
requestCameraPermissionLauncher =
registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
if (granted) {
Log.d(TAG, "registerCameraPermission - Camera Permission Granted")
openCamera()
} else {
Log.d(TAG, "registerCameraPermission - Camera Permission NOT Granted")
requestCameraPermission()
}
}
}
private fun registerStoragePermission() {
requestStoragePermissionLauncher =
registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
if (granted) {
Log.d(TAG, "registerStoragePermission - Storage Permission Granted")
viewGallery()
} else {
Log.d(TAG, "registerStoragePermission - Storage Permission NOT Granted")
requestStoragePermission()
}
}
}
private fun registerCameraLauncher() {
cameraLauncher =
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
if (result.resultCode == Activity.RESULT_OK) {
val data: Intent? = result.data
if (data == null) {
return@registerForActivityResult
}
val extras = data.extras
imageBitmap = extras!!["data"] as Bitmap
file = FileUtils.createFile(requireContext(),
getString(R.string.app_name),
"my_profile_image.png"
)
//FileUtils.saveBitmap(imageBitmap, file);
val imageLocalPath = FileUtils.saveImageToInternalStorage(file, imageBitmap)
SharedPreferencesUtils.setProfilePath(requireActivity(), imageLocalPath)
profileFragmentBinding.imageViewCircleNoStroke.setImageBitmap(imageBitmap)
profileFragmentBinding.imageViewCircleNoStroke.setScaleType(ImageView.ScaleType.CENTER_CROP)
}
}
}
private fun registerGalleryLauncher() {
galleryLauncher =
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
if (result.resultCode == Activity.RESULT_OK) {
val data: Intent? = result.data
if (data == null) {
return@registerForActivityResult
}
val uri = data.data
var imageLocalPath = File(FileUtils.getPathReal(requireActivity(), uri!!))
file = imageLocalPath.absoluteFile
SharedPreferencesUtils.setProfilePath(requireActivity(), imageLocalPath.absolutePath)
Glide.with(requireActivity()).load(uri)
.into(profileFragmentBinding.imageViewCircleNoStroke)
profileFragmentBinding.imageViewCircleNoStroke.setScaleType(ImageView.ScaleType.CENTER_CROP)
}
}
}
private fun showImageUploadOptions() {
val mDialog = activity.let { Dialog(it!!) }
mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
mDialog.setContentView(R.layout.dialog_profile_image_option)
mDialog.window!!.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
//val mAlertMessageTv = mDialog.findViewById<View>(R.id.id_alert_tv) as TextView
//mAlertMessageTv.text = message
galleryLl = mDialog.findViewById<View>(R.id.id_gallery_ll) as LinearLayout
cameraLl = mDialog.findViewById<View>(R.id.id_camera_ll) as LinearLayout
removePhotoLl = mDialog.findViewById<View>(R.id.id_remove_photo_ll) as LinearLayout
galleryLl.setOnClickListener {
CallStoragePermission()
mDialog.dismiss()
}
cameraLl.setOnClickListener {
CallCameraPermission()
mDialog.dismiss()
}
removePhotoLl.setOnClickListener {
CallRemovePhoto()
mDialog.dismiss()
}
mDialog.setCancelable(true)
mDialog.show()
val metrics = resources.displayMetrics
val width = metrics.widthPixels
val height = metrics.heightPixels
mDialog.window!!.setLayout(
width,
LinearLayout.LayoutParams.WRAP_CONTENT
)
}
fun CallStoragePermission() {
if (!Status_checkReadExternalStoragePermission()) {
requestStoragePermissionLauncher.launch(Manifest.permission.READ_EXTERNAL_STORAGE)
} else {
viewGallery()
}
}
private fun Status_checkReadExternalStoragePermission(): Boolean {
val permissionState = ActivityCompat.checkSelfPermission(
requireActivity(),
Manifest.permission.READ_EXTERNAL_STORAGE
)
return permissionState == PackageManager.PERMISSION_GRANTED
}
private fun requestCameraPermission() {
when {
ContextCompat.checkSelfPermission(
requireContext(),
Manifest.permission.CAMERA
) == PackageManager.PERMISSION_GRANTED -> {
Log.d(TAG, "requestCameraPermission - Camera Permission Granted")
openCamera()
// The permission is granted
// you can go with the flow that requires permission here
}
shouldShowRequestPermissionRationale(Manifest.permission.CAMERA) -> {
// This case means user previously denied the permission
// So here we can display an explanation to the user
// That why exactly we need this permission
Log.d(TAG, "requestCameraPermission - Camera Permission NOT Granted")
showPermissionAlert(
getString(R.string.camera_permission),
getString(R.string.camera_permission_denied),
getString(R.string.ok_caps),
getString(R.string.cancel_caps)
) { requestCameraPermissionLauncher.launch(Manifest.permission.CAMERA) }
}
else -> {
// Everything is fine you can simply request the permission
showPermissionAlert(
getString(R.string.camera_permission),
getString(R.string.camera_permission_denied),
getString(R.string.settings_caps),
getString(R.string.cancel_caps)
) {
val intent = Intent()
intent.action = Settings.ACTION_APPLICATION_DETAILS_SETTINGS
val uri = Uri.fromParts(
"package",
BuildConfig.APPLICATION_ID, null
)
intent.data = uri
intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
startActivity(intent)
}
}
}
}
private fun requestStoragePermission() {
when {
ContextCompat.checkSelfPermission(
requireContext(),
Manifest.permission.READ_EXTERNAL_STORAGE
) == PackageManager.PERMISSION_GRANTED -> {
Log.d(TAG, "requestStoragePermission - Storage Permission Granted")
viewGallery()
// The permission is granted
// you can go with the flow that requires permission here
}
shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE) -> {
// This case means user previously denied the permission
// So here we can display an explanation to the user
// That why exactly we need this permission
Log.d(TAG, "requestStoragePermission - Storage Permission NOT Granted")
showPermissionAlert(
getString(R.string.read_storage_permission_required),
getString(R.string.storage_permission_denied),
getString(R.string.ok_caps),
getString(R.string.cancel_caps)
) { requestStoragePermissionLauncher.launch(Manifest.permission.READ_EXTERNAL_STORAGE) }
}
else -> {
// Everything is fine you can simply request the permission
showPermissionAlert(
getString(R.string.read_storage_permission_required),
getString(R.string.storage_permission_denied),
getString(R.string.settings_caps),
getString(R.string.cancel_caps)
) {
val intent = Intent()
intent.action = Settings.ACTION_APPLICATION_DETAILS_SETTINGS
val uri = Uri.fromParts(
"package",
BuildConfig.APPLICATION_ID, null
)
intent.data = uri
intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
startActivity(intent)
}
}
}
}
private fun showPermissionAlert(
title: String,
message: String,
ok: String,
cancel: String,
function: () -> Unit
) {
val mDialog = requireActivity().let { Dialog(it) }
mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE)
mDialog.setContentView(R.layout.dialog_permission_alert)
mDialog.window!!.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
val mTitleTv = mDialog.findViewById<View>(R.id.id_title_tv) as AppCompatTextView
mTitleTv.text = title
val mMessageTv = mDialog.findViewById<View>(R.id.id_message_tv) as AppCompatTextView
mMessageTv.text = message
val mNoBtn = mDialog.findViewById<View>(R.id.no_btn) as AppCompatTextView
mNoBtn.text = cancel
val mYesBtn = mDialog.findViewById<View>(R.id.yes_btn) as AppCompatTextView
mYesBtn.text = ok
mYesBtn.setOnClickListener {
function.invoke()
mDialog.dismiss()
}
mNoBtn.setOnClickListener { mDialog.dismiss() }
mDialog.setCancelable(true)
mDialog.show()
val metrics = resources.displayMetrics
val width = metrics.widthPixels
val height = metrics.heightPixels
mDialog.window!!.setLayout(
width,
LinearLayout.LayoutParams.WRAP_CONTENT
)
}
fun viewGallery() {
val intentDocument = Intent(Intent.ACTION_GET_CONTENT)
intentDocument.type = "image/*"
intentDocument.putExtra(
Constants.REQUEST_CODE,
Constants.REQUEST_PHOTO_FROM_GALLERY
)
galleryLauncher.launch(intentDocument)
}
fun openCamera() {
val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
takePictureIntent.putExtra(
Constants.REQUEST_CODE,
Constants.REQUEST_PERMISSIONS_REQUEST_CODE_CAMERA
)
cameraLauncher.launch(takePictureIntent)
}
fun CallCameraPermission() {
if (!Status_checkCameraPermission()) {
requestCameraPermissionLauncher.launch(Manifest.permission.CAMERA)
} else {
openCamera()
}
}
private fun Status_checkCameraPermission(): Boolean {
val camera = ActivityCompat.checkSelfPermission(
requireActivity(),
Manifest.permission.CAMERA
)
return camera == PackageManager.PERMISSION_GRANTED
}
我还想知道用户是否选择了“never ask again”。我已经实现了一个“几乎解决方案”与一个丑陋的旗帜，但在我告诉你如何，我将告诉你我的动机:
I would like to offer the permission referring functionality initially. If the user uses it and has no rights, he/she gets the either the 1th dialog from above or both the 2nd and 3rd. When the user has chosen 'Never ask again' I would like to disable the functionality and to display it differently. - My action is triggered by a spinner text entry, I would also like to add '(Permission revoked)' to the label text displayed. This shows to the user: 'There is functionality but I cannot use it, due to my permission settings.' However, this does not seem to be possible, as I cannot check whether or not 'Never ask again' has been chosen.
I came to a solution I can live with by having my functionality always enabled with an active permission check. I am showing a Toast message in onRequestPermissionsResult() in case of a negative response but only if I have not shown my custom rationale popup. So if the user has chosen 'Never ask again' he gets a toast message only. If the user is reluctant to chose 'never ask again' he gets only the custom rationale and the permission request popup by the operation system but not toast, as three notifications in a row would be too much pain.
我发现这个问题的方法对我来说有点新鲜。我必须保留一个参考，如果用户曾经选择了一个决定。通过这种方式，如果权限没有被授予，我可以告诉用户是第一次在那里，并且应该提示看到权限弹出，或者用户暂时或永久地拒绝它。
psudocode:
if( granted ) {
// you are set
} else if( requiresRationale() ) {
// in the ui let the user know he has to tap and launch permission
button.onSetClickListener { requestPermission() }
} else if( sharedPreferences.getBoolean("permission", false) ) {
// so user has already decided to deny permission, then it is permanent
launchAppSettings()
} else {
// user's first encounter, request permission
requestPermission()
}
演示文件以GIF格式附在自述文件中。 https://github.com/juanmendez/android-sdk-updates/tree/api/android-permissions/single
OnRequestPermissionResult-free和shouldshowrequestpermissionrationalfree方法:
public static void requestDangerousPermission(AppCompatActivity activity, String permission) {
if (hasPermission(activity, permission)) return;
requestPermission();
new Handler().postDelayed(() -> {
if (activity.getLifecycle().getCurrentState() == Lifecycle.State.RESUMED) {
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
intent.setData(Uri.parse("package:" + context.getPackageName()));
context.startActivity(intent);
}
}, 250);
}
如果没有权限弹出，250ms后打开设备设置(如果选择了“Never ask again”，就是这种情况)。
