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

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
}

其他回答

如果你想检测所有的“状态”(第一次被拒绝,刚刚被拒绝,刚刚被“Never Ask Again”拒绝或永久拒绝),你可以做以下事情:

创建2个布尔值:

private boolean beforeClickPermissionRat;
private boolean afterClickPermissionRat;

在请求允许之前设置第一个:

beforeClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);

在你的onRequestPermissionsResult方法中设置第二个:

afterClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);

使用下面的“真值表”在onRequestPermissionsResult()中做任何你需要的事情(在检查你仍然没有权限之后):

// before after
// FALSE  FALSE  =  Was denied permanently, still denied permanently --> App Settings
// FALSE  TRUE   =  First time deny, not denied permanently yet --> Nothing
// TRUE   FALSE  =  Just been permanently denied --> Changing my caption to "Go to app settings to edit permissions"
// TRUE   TRUE   =  Wasn't denied permanently, still not denied permanently --> Nothing

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:)

扩展上面mVck的答案,下面的逻辑确定是否“Never ask again”已经为给定的权限请求进行了检查:

bool bStorage = grantResults[0] == Permission.Granted;
bool bNeverAskForStorage =
    !bStorage && (
        _bStorageRationaleBefore == true  && _bStorageRationaleAfter == false ||
        _bStorageRationaleBefore == false && _bStorageRationaleAfter == false
    );

摘自下面(完整的例子见这个答案)

private bool _bStorageRationaleBefore;
private bool _bStorageRationaleAfter;        
private const int ANDROID_PERMISSION_REQUEST_CODE__SDCARD = 2;
//private const int ANDROID_PERMISSION_REQUEST_CODE__CAMERA = 1;
private const int ANDROID_PERMISSION_REQUEST_CODE__NONE = 0;

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
{
    base.OnRequestPermissionsResult(requestCode, permissions, grantResults);

    switch (requestCode)
    {
        case ANDROID_PERMISSION_REQUEST_CODE__SDCARD:               
            _bStorageRationaleAfter = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
            bool bStorage = grantResults[0] == Permission.Granted;
            bool bNeverAskForStorage =
                !bStorage && (
                    _bStorageRationaleBefore == true  && _bStorageRationaleAfter == false ||
                    _bStorageRationaleBefore == false && _bStorageRationaleAfter == false
                );      
            break;                
    }
}

private List<string> GetRequiredPermissions(out int requestCode)
{
    // Android v6 requires explicit permission granting from user at runtime for security reasons            
    requestCode = ANDROID_PERMISSION_REQUEST_CODE__NONE; // 0
    List<string> requiredPermissions = new List<string>();

    _bStorageRationaleBefore = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
    Permission writeExternalStoragePerm = ApplicationContext.CheckSelfPermission(Android.Manifest.Permission.WriteExternalStorage);
    //if(extStoragePerm == Permission.Denied)
    if (writeExternalStoragePerm != Permission.Granted)
    {
        requestCode |= ANDROID_PERMISSION_REQUEST_CODE__SDCARD;
        requiredPermissions.Add(Android.Manifest.Permission.WriteExternalStorage);
    }

    return requiredPermissions;
}

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);

        // Android v6 requires explicit permission granting from user at runtime for security reasons
        int requestCode;
        List<string> requiredPermissions = GetRequiredPermissions(out requestCode);
        if (requiredPermissions != null && requiredPermissions.Count > 0)
        {
            if (requestCode >= ANDROID_PERMISSION_REQUEST_CODE__SDCARD)                    
            {
                _savedInstanceState = savedInstanceState;
                RequestPermissions(requiredPermissions.ToArray(), requestCode);
                return;
            }
        }
    }            

    OnCreate2(savedInstanceState);
}

你可以使用

shouldShowRequestPermissionRationale()

内部

onRequestPermissionsResult()

请看下面的例子:

当用户点击按钮时检查是否有权限:

@Override
public void onClick(View v) {
    if (v.getId() == R.id.appCompatBtn_changeProfileCoverPhoto) {
        if (Build.VERSION.SDK_INT < 23) { // API < 23 don't need to ask permission
            navigateTo(MainActivity.class); // Navigate to activity to change photos
        } else {
            if (ContextCompat.checkSelfPermission(SettingsActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                    != PackageManager.PERMISSION_GRANTED) {
                // Permission is not granted yet. Ask for permission...
                requestWriteExternalPermission();
            } else {
                // Permission is already granted, good to go :)
                navigateTo(MainActivity.class);
            }
        } 
    }
}

当用户回答权限对话框时,我们将进入onRequestPermissionResult:

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    if (requestCode == WRITE_EXTERNAL_PERMISSION_REQUEST_CODE) {
        // Case 1. Permission is granted.  
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {  
            if (ContextCompat.checkSelfPermission(SettingsActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                    == PackageManager.PERMISSION_GRANTED) {
                // Before navigating, I still check one more time the permission for good practice.
                navigateTo(MainActivity.class);
            }
        } else { // Case 2. Permission was refused
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                // Case 2.1. shouldShowRequest... returns true because the
                // permission was denied before. If it is the first time the app is running we will 
                // end up in this part of the code. Because he need to deny at least once to get 
                // to onRequestPermissionsResult. 
                Snackbar snackbar = Snackbar.make(findViewById(R.id.relLayout_container), R.string.you_must_verify_permissions_to_send_media, Snackbar.LENGTH_LONG);
                snackbar.setAction("VERIFY", new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        ActivityCompat.requestPermissions(SettingsActivity.this
                                , new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}
                                , WRITE_EXTERNAL_PERMISSION_REQUEST_CODE);
                    }
                });
                snackbar.show();
            } else {
                // Case 2.2. Permission was already denied and the user checked "Never ask again". 
                // Navigate user to settings if he choose to allow this time.
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setMessage(R.string.instructions_to_turn_on_storage_permission)
                        .setPositiveButton(getString(R.string.settings), new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Intent settingsIntent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                                Uri uri = Uri.fromParts("package", getPackageName(), null);
                                settingsIntent.setData(uri);
                                startActivityForResult(settingsIntent, 7);
                            }
                        })
                        .setNegativeButton(getString(R.string.not_now), null);
                Dialog dialog = builder.create();
                dialog.show();
            }
        }
    }

}

我必须实现相机的动态权限。有三种可能的情况:允许2。否认,3。别再问了。

 @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

    for (String permission : permissions) {
        if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), permission)) {
            //denied
            Log.e("denied", permission);
        } else {
            if (ActivityCompat.checkSelfPermission(getActivity(), permission) == PackageManager.PERMISSION_GRANTED) {
                //allowed
                Log.e("allowed", permission);
            } else {
                //set to never ask again
                Log.e("set to never ask again", permission);
                //do something here.
            }
        }
    }
    if (requestCode != MaterialBarcodeScanner.RC_HANDLE_CAMERA_PERM) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        return;
    }
    if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
        return;
    } else {
        //set to never ask again
        Log.e("set to never ask again", permissions[0]);
    }
    DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    };
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setTitle("Error")
            .setMessage(R.string.no_camera_permission)
            .setPositiveButton(android.R.string.ok, listener)
            .show();


}

private void insertDummyContactWrapper() {
        int hasWriteContactsPermission = checkSelfPermission(Manifest.permission.CAMERA);
        if (hasWriteContactsPermission != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.CAMERA},
                    REQUEST_CODE_ASK_PERMISSIONS);
            return;
        }
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
    }

private int checkSelfPermission(String camera) {
    if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)
            != PackageManager.PERMISSION_GRANTED) {
        return REQUEST_CODE_ASK_PERMISSIONS;
    } else {
        return REQUEST_NOT_CODE_ASK_PERMISSIONS;
    }
}