java - 相机在未经相机许可的情况下工作

Question

我既没有在 list 中也没有通过编程方式包含相机许可，但我的应用程序仍然打开了相机。到现在我一直在想的是相机权限是用来打开相机的，但是这里完全不同。所以需要一些帮助来了解为什么相机在没有授予权限的情况下工作。感谢您的帮助。这是我的代码

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_CAMERA = 1;
    private static final int SELECT_FILE = 2;
    String userChoosenTask;
    ImageView ivImage;
    Button btselect;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ivImage = (ImageView) findViewById(R.id.ivImage);
        btselect = (Button) findViewById(R.id.btnSelectPhoto);
        btselect.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                selectImage();
            }
        });
    }

    private void selectImage() {
        final CharSequence[] items = {"Take Photo", "Choose from Library", "Cancel"};
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle("Add Photo!");
        builder.setItems(items, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int item) {
                boolean result = Utility.checkPermission(MainActivity.this);

                if (items[item].equals("Take Photo")) {
                    userChoosenTask = "Take Photo";
                    if (result)
                        cameraIntent();
                } else if (items[item].equals("Choose from Library")) {
                    userChoosenTask = "Choose from Library";
                    if (result)
                        galleryIntent();
                } else if (items[item].equals("Cancel")) {
                    dialog.dismiss();
                }
            }
        });
        builder.show();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (userChoosenTask.equals("Take Photo"))
                        cameraIntent();
                    else if (userChoosenTask.equals("Choose from Library"))
                        galleryIntent();
                } else {
//code for deny
                }
                break;
        }
    }

    private void cameraIntent() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, REQUEST_CAMERA);
    }

    private void galleryIntent() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Select File"), SELECT_FILE);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {
            if (SELECT_FILE == requestCode)
                onSelectFromGalleryResult(data);
            else if (requestCode == REQUEST_CAMERA)
                onCaptureImageResult(data);
        }
    }

    @SuppressWarnings("deprecation")
    private void onSelectFromGalleryResult(Intent data) {
        Bitmap bm = null;
        if (data != null) {
            try {
                bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        ivImage.setImageBitmap(bm);
    }

    private void onCaptureImageResult(Intent data) {
        Bitmap thumbnail = (Bitmap) data.getExtras().get("data");

        // CALL THIS METHOD TO GET THE URI FROM THE BITMAP
        Uri tempUri = getImageUri(getApplicationContext(), thumbnail);

        // CALL THIS METHOD TO GET THE ACTUAL PATH
        File finalFile = new File(getRealPathFromURI(tempUri));
        Bitmap finalimg = ExifUtil.rotateBitmap(finalFile.toString(), thumbnail);
        ivImage.setImageBitmap(thumbnail);
    }

    public Uri getImageUri(Context inContext, Bitmap inImage) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
        return Uri.parse(path);
    }

    public String getRealPathFromURI(Uri uri) {
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);
        cursor.moveToFirst();
        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
        return cursor.getString(idx);
    }
}

ExifUtil.java

public class ExifUtil {

    public static Bitmap rotateBitmap(String src, Bitmap bitmap) {
        try {
            int orientation = getExifOrientation(src);

            if (orientation == 1) {
                return bitmap;
            }

            Matrix matrix = new Matrix();
            switch (orientation) {
            case 2:
                matrix.setScale(-1, 1);
                break;
            case 3:
                matrix.setRotate(180);
                break;
            case 4:
                matrix.setRotate(180);
                matrix.postScale(-1, 1);
                break;
            case 5:
                matrix.setRotate(90);
                matrix.postScale(-1, 1);
                break;
            case 6:
                matrix.setRotate(90);
                break;
            case 7:
                matrix.setRotate(-90);
                matrix.postScale(-1, 1);
                break;
            case 8:
                matrix.setRotate(-90);
                break;
            default:
                return bitmap;
            }

            try {
                Bitmap oriented = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
                bitmap.recycle();
                return oriented;
            } catch (OutOfMemoryError e) {
                e.printStackTrace();
                return bitmap;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } 

        return bitmap;
    }

    private static int getExifOrientation(String src) throws IOException {
        int orientation = 1;

        try {
            /**
             * if your are targeting only api level >= 5
             * ExifInterface exif = new ExifInterface(src);
             * orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
             */
            if (Build.VERSION.SDK_INT >= 5) {
                Class<?> exifClass = Class.forName("android.media.ExifInterface");
                Constructor<?> exifConstructor = exifClass.getConstructor(new Class[] { String.class });
                Object exifInstance = exifConstructor.newInstance(new Object[] { src });
                Method getAttributeInt = exifClass.getMethod("getAttributeInt", new Class[] { String.class, int.class });
                Field tagOrientationField = exifClass.getField("TAG_ORIENTATION");
                String tagOrientation = (String) tagOrientationField.get(null);
                orientation = (Integer) getAttributeInt.invoke(exifInstance, new Object[] { tagOrientation, 1});
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }

        return orientation;
    }
}

Utility.java

public class Utility {
    public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 123;
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    public static boolean checkPermission(final Context context)
    {
        int currentAPIVersion = Build.VERSION.SDK_INT;
        if(currentAPIVersion>=android.os.Build.VERSION_CODES.M)
        {
            if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
                    alertBuilder.setCancelable(true);
                    alertBuilder.setTitle("Permission necessary");
                    alertBuilder.setMessage("External storage permission 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.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                        }
                    });
                    AlertDialog alert = alertBuilder.create();
                    alert.show();
                } else {
                    ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                }
                return false;
            } else {
                return true;
            }
        } else {
            return true;
        }
    }
}

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.takeimagedemo">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Answer 1

如果您只是通过 Intent 启动相机应用程序，则不需要相机许可。启动任何应用程序都不需要任何许可。 当您直接访问相机资源或使用相机 api 时，您需要相机权限。

android.permission.READ_EXTERNAL_STORAGE & 
android.permission.WRITE_EXTERNAL_STORAGE

仅因为您将捕获的图像存储在 SD 卡或手机内存中，才需要上述权限。

希望这些对你有所帮助。