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

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.

其他回答

我也遇到过同样的问题,但我解决了。为了简化工作,我编写了一个util类来处理运行时权限。

public class PermissionUtil {
    /*
    * Check if version is marshmallow and above.
    * Used in deciding to ask runtime permission
    * */
    public static boolean shouldAskPermission() {
        return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M);
    }
private static boolean shouldAskPermission(Context context, String permission){
        if (shouldAskPermission()) {
            int permissionResult = ActivityCompat.checkSelfPermission(context, permission);
            if (permissionResult != PackageManager.PERMISSION_GRANTED) {
                return true;
            }
        }
        return false;
    }
public static void checkPermission(Context context, String permission, PermissionAskListener listener){
/*
        * If permission is not granted
        * */
        if (shouldAskPermission(context, permission)){
/*
            * If permission denied previously
            * */
            if (((Activity)context).shouldShowRequestPermissionRationale(permission)) {
                listener.onPermissionPreviouslyDenied();
            } else {
                /*
                * Permission denied or first time requested
                * */
if (PreferencesUtil.isFirstTimeAskingPermission(context, permission)) {
                    PreferencesUtil.firstTimeAskingPermission(context, permission, false);
                    listener.onPermissionAsk();
                } else {
                    /*
                    * Handle the feature without permission or ask user to manually allow permission
                    * */
                    listener.onPermissionDisabled();
                }
            }
        } else {
            listener.onPermissionGranted();
        }
    }
/*
    * Callback on various cases on checking permission
    *
    * 1.  Below M, runtime permission not needed. In that case onPermissionGranted() would be called.
    *     If permission is already granted, onPermissionGranted() would be called.
    *
    * 2.  Above M, if the permission is being asked first time onPermissionAsk() would be called.
    *
    * 3.  Above M, if the permission is previously asked but not granted, onPermissionPreviouslyDenied()
    *     would be called.
    *
    * 4.  Above M, if the permission is disabled by device policy or the user checked "Never ask again"
    *     check box on previous request permission, onPermissionDisabled() would be called.
    * */
    public interface PermissionAskListener {
/*
        * Callback to ask permission
        * */
        void onPermissionAsk();
/*
        * Callback on permission denied
        * */
        void onPermissionPreviouslyDenied();
/*
        * Callback on permission "Never show again" checked and denied
        * */
        void onPermissionDisabled();
/*
        * Callback on permission granted
        * */
        void onPermissionGranted();
    }
}

PreferenceUtil方法如下。

public static void firstTimeAskingPermission(Context context, String permission, boolean isFirstTime){
SharedPreferences sharedPreference = context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE;
 sharedPreference.edit().putBoolean(permission, isFirstTime).apply();
 }
public static boolean isFirstTimeAskingPermission(Context context, String permission){
return context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE).getBoolean(permission, true);
}

现在,您所需要的就是使用带有适当参数的方法* checkPermission*。

举个例子,

PermissionUtil.checkPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    new PermissionUtil.PermissionAskListener() {
                        @Override
                        public void onPermissionAsk() {
                            ActivityCompat.requestPermissions(
                                    thisActivity,
              new String[]{Manifest.permission.READ_CONTACTS},
                            REQUEST_EXTERNAL_STORAGE
                            );
                        }
@Override
                        public void onPermissionPreviouslyDenied() {
                       //show a dialog explaining permission and then request permission
                        }
@Override
                        public void onPermissionDisabled() {
Toast.makeText(context, "Permission Disabled.", Toast.LENGTH_SHORT).show();
                        }
@Override
                        public void onPermissionGranted() {
                            readContacts();
                        }
                    });

我的应用程序如何知道用户是否选中了“永不再问”?

如果用户勾选“永不再问”,你将得到onPermissionDisabled上的回调。

快乐编码:)

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。

为了准确地回答这个问题,当用户按下“永不再问”时会发生什么?

重写的方法/函数

onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray)

grantResult数组显示为空,你可以在这里做些什么?但不是最好的做法。

如何处理“永不再问”?

我正在使用Fragment,它需要READ_EXTERNAL_STORAGE权限。

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        when {
            isReadPermissionsGranted() -> {

                /**
                 * Permissions has been Granted
                 */

                getDirectories()
            }

            isPermissionDeniedBefore() -> {

                /**
                 * User has denied before, explain why we need the permission and ask again
                 */

                updateUIForDeniedPermissions()
                checkIfPermissionIsGrantedNow()

            }
            else -> {

                /**
                 * Need to ask For Permissions, First Time
                 */

                checkIfPermissionIsGrantedNow()

                /**
                 * If user selects, "Dont Ask Again" it will never ask again! so just update the UI for Denied Permissions
                 */

                updateUIForDeniedPermissions()

            }
        }
    }

其他的函数是微不足道的。

// Is Read Write Permissions Granted
fun isReadWritePermissionGranted(context: Context): Boolean {
    return (ContextCompat.checkSelfPermission(
        context as Activity,
        Manifest.permission.READ_EXTERNAL_STORAGE
    ) == PackageManager.PERMISSION_GRANTED) and
            (ContextCompat.checkSelfPermission(
                context,
                Manifest.permission.WRITE_EXTERNAL_STORAGE
            ) == PackageManager.PERMISSION_GRANTED)
}

fun isReadPermissionDenied(context: Context) : Boolean {
    return ActivityCompat.shouldShowRequestPermissionRationale(
        context as Activity,
        PermissionsUtils.READ_EXTERNAL_STORAGE_PERMISSIONS)
}

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
}