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
shouldShowRequestPermissionRationale()方法可以用来检查用户是否选择了“never asked again”选项并拒绝了权限。 有很多代码示例，所以我宁愿解释如何将它用于这样的目的，因为我认为它的名称和实现使它比实际情况更加复杂。
正如在运行时请求权限中解释的那样，如果选项“never ask again”可见，该方法返回true，否则返回false;因此，它在第一次显示对话框时返回false，然后从第二次开始返回true，只有当用户拒绝选择该选项的权限时，它才会再次返回false。
要检测这种情况，您可以检测序列false-true-false，或者(更简单)您可以使用一个标记来跟踪对话框显示的初始时间。在此之后，该方法返回true或false，其中false将允许您检测何时选择该选项。
其他回答
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
switch (requestCode) {
case PERMISSIONS_REQUEST_EXTERNAL_STORAGE: {
if (grantResults.length > 0) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Denied
} else {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
// To what you want
} else {
// Bob never checked click
}
}
}
}
}
}
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)。
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
}
对每一种许可情况的完整解释
/**
* Case 1: User doesn't have permission
* Case 2: User has permission
*
* Case 3: User has never seen the permission Dialog
* Case 4: User has denied permission once but he din't clicked on "Never Show again" check box
* Case 5: User denied the permission and also clicked on the "Never Show again" check box.
* Case 6: User has allowed the permission
*
*/
public void handlePermission() {
if (ContextCompat.checkSelfPermission(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
// This is Case 1. Now we need to check further if permission was shown before or not
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// This is Case 4.
} else {
// This is Case 3. Request for permission here
}
} else {
// This is Case 2. You have permission now you can do anything related to it
}
}
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// This is Case 2 (Permission is now granted)
} else {
// This is Case 1 again as Permission is not granted by user
//Now further we check if used denied permanently or not
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// case 4 User has denied permission but not permanently
} else {
// case 5. Permission denied permanently.
// You can open Permission setting's page from here now.
}
}
}
在阅读了一些答案后，我发现了许多冗长而令人困惑的答案 我的结论是
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.READ_EXTERNAL_STORAGE))
Toast.makeText(this, "permanently denied", Toast.LENGTH_SHORT).show();
