Question

我正在做一个按钮点击扫描条形码的应用程序，它可以正常工作到Lollipop版本。当我来到棉花糖时，它停止了工作。这是错误：

camerabase连接到相机0时发生错误

它强迫我通过以下方式启用权限：

设置 - ＆gt;申请 - ＆gt;我的应用 - ＆gt;相机。

我的问题是如何在Marshmallow中自动允许相机对我的应用程序的许可，或者要求用户在运行时打开相机。屏幕截图：

Answer 1

下面我编写了一个用于授予Camera的运行时权限的代码。有一个String数组，您可以在其中提供多个请求，这些请求在运行时需要授予。

public class MainActivity extends AppCompatActivity {
    private static final int PERMISSION_REQUEST_CODE = 200;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (checkPermission()) {
        //main logic or main code

       // . write your main code to execute, It will execute if the permission is already given.

        } else {
            requestPermission();
        }
    }

    private boolean checkPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            // Permission is not granted
            return false;
        }
        return true;
    }

    private void requestPermission() {

        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.CAMERA},
                PERMISSION_REQUEST_CODE);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case PERMISSION_REQUEST_CODE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(getApplicationContext(), "Permission Granted", Toast.LENGTH_SHORT).show();

                    // main logic
                } else {
                    Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_SHORT).show();
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                                != PackageManager.PERMISSION_GRANTED) {
                            showMessageOKCancel("You need to allow access permissions",
                                    new DialogInterface.OnClickListener() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {
                                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                                requestPermission();
                                            }
                                        }
                                    });
                        }
                    }
                }
                break;
        }
    }

    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new AlertDialog.Builder(MainActivity.this)
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", null)
                .create()
                .show();
    }
}

Answer 2

    if (ContextCompat.checkSelfPermission(getContext(),
            Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {

        if (ActivityCompat.shouldShowRequestPermissionRationale((Activity)
                getContext(), Manifest.permission.CAMERA)) {


        } else {
            ActivityCompat.requestPermissions((Activity) getContext(), 
                    new String[]{Manifest.permission.CAMERA},
                    MY_PERMISSIONS_REQUEST_CAMERA);
        }

    }

Answer 3

RxPermission是向用户询问权限的最佳库。

要获得摄像头许可，解决方法是这样的。

1）首先在manifest.xml中添加这些权限（或您需要的权限）。

<uses-permission android:name="android.permission.CAMERA" />

2）然后在您的活动中向用户询问运行时权限。

RxPermissions rxPermissions = new RxPermissions(this);
rxPermissions
.request(Manifest.permission.CAMERA) // ask single or multiple permission once
.subscribe(granted -> {
    if (granted) {
       // All requested permissions are granted
    } else {
       // At least one permission is denied
    }
});

将此库添加到您的build.gradle

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.tbruyelle:rxpermissions:0.10.1'
    implementation 'com.jakewharton.rxbinding2:rxbinding:2.1.1'
}

这不容易吗？

Answer 4

This sample Profile project demonstrates how to get Read Storage and Camera Permission in Android and also how to handle when the user selects DENY & DON'T ASK AGAIN.

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
}

Answer 5

这是实现运行时权限的完整代码

在manifest中添加摄像头权限

声明此变量

  public static final int RequestPermissionCode = 7;

在checkAndroidVersion()中调用此方法oncreate()

private void checkAndroidVersion() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            checkAndRequestPermissions();

        } else {
            // code for lollipop and pre-lollipop devices
        }

    }


private boolean checkAndRequestPermissions() {
        int camera = ContextCompat.checkSelfPermission(getActivity(),
                Manifest.permission.CAMERA);
        int wtite = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE);
        int read = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE);
        List<String> listPermissionsNeeded = new ArrayList<>();
        if (wtite != PackageManager.PERMISSION_GRANTED) {
            listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
        }
        if (camera != PackageManager.PERMISSION_GRANTED) {
            listPermissionsNeeded.add(Manifest.permission.CAMERA);
        }
        if (read != PackageManager.PERMISSION_GRANTED) {
            listPermissionsNeeded.add(Manifest.permission.READ_EXTERNAL_STORAGE);
        }
        if (!listPermissionsNeeded.isEmpty()) {
            ActivityCompat.requestPermissions(getActivity(), listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]), REQUEST_ID_MULTIPLE_PERMISSIONS);
            return false;
        }
        return true;
    }


@Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        Log.d("in fragment on request", "Permission callback called-------");
        switch (requestCode) {
            case REQUEST_ID_MULTIPLE_PERMISSIONS: {

                Map<String, Integer> perms = new HashMap<>();
                // Initialize the map with both permissions
                perms.put(Manifest.permission.WRITE_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.CAMERA, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.READ_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
                // Fill with actual results from user
                if (grantResults.length > 0) {
                    for (int i = 0; i < permissions.length; i++)
                        perms.put(permissions[i], grantResults[i]);
                    // Check for both permissions
                    if (perms.get(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
                            && perms.get(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED && perms.get(Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
                        Log.d("in fragment on request", "CAMERA & WRITE_EXTERNAL_STORAGE READ_EXTERNAL_STORAGE permission granted");
                        // process the normal flow
                        //else any one or both the permissions are not granted
                    } else {
                        Log.d("in fragment on request", "Some permissions are not granted ask again ");
                        //permission is denied (this is the first time, when "never ask again" is not checked) so ask again explaining the usage of permission
//                        // shouldShowRequestPermissionRationale will return true
                        //show the dialog or snackbar saying its necessary and try again otherwise proceed with setup.
                        if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) || ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.CAMERA) || ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE)) {
                            showDialogOK("Camera and Storage Permission required for this app",
                                    new DialogInterface.OnClickListener() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {
                                            switch (which) {
                                                case DialogInterface.BUTTON_POSITIVE:
                                                    checkAndRequestPermissions();
                                                    break;
                                                case DialogInterface.BUTTON_NEGATIVE:
                                                    // proceed with logic by disabling the related features or quit the app.
                                                    break;
                                            }
                                        }
                                    });
                        }
                        //permission is denied (and never ask again is  checked)
                        //shouldShowRequestPermissionRationale will return false
                        else {
                            Toast.makeText(getActivity(), "Go to settings and enable permissions", Toast.LENGTH_LONG)
                                    .show();
                            //                            //proceed with logic by disabling the related features or quit the app.
                        }
                    }
                }
            }
        }

    }

    private void showDialogOK(String message, DialogInterface.OnClickListener okListener) {
        new AlertDialog.Builder(getActivity())
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", okListener)
                .create()
                .show();
    }

Answer 6

这可能会有所帮助：

if (ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
{
    if(ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.CAMERA))
    {
        AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
        alertBuilder.setCancelable(true);
        alertBuilder.setTitle("Permission necessary");
        alertBuilder.setMessage("CAMERA is necessary");
        alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
            @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
            public void onClick(DialogInterface dialog, int which) {
                ActivityCompat.requestPermissions((Activity) context, 
                new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUESTS);
            }
        });
        AlertDialog alert = alertBuilder.create();
        alert.show();
    } else {
        ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUESTS);
    }
    return false;
} else {
    return true;
}

MY_PERMISSIONS_REQUESTS是请求代码的最终值。

它适用于我。

Answer 7

在清单文件中定义它之后，可以使用Aaper：https://github.com/LikeTheSalad/aaper来代替本机解决方案，这是一种更友好的选择：

@EnsurePermissions(permissions = [Manifest.permission.CAMERA])
private fun takePhoto() {
    // Your code that needs the camera permission granted.
}

免责声明，我是Aaper的创建者。

如何询问Camera的运行时权限

7 个答案: