android - 选择了闪光模式，但相机无法使用这些闪光模式拍摄图像

Question

我正在开发一个涉及手动相机的应用程序，其中它有自己的闪光灯按钮，可以从关闭到打开再到自动旋转。我正在调用带有 onClickListener 的 switch 语句来执行此操作。

   private void setFlash() {
    switch (mFlashMode) {
        case CONTROL_AE_MODE_OFF:
            mCaptureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON);
            useFlashButton.setImageResource(R.drawable.flash_on);
            mFlashMode = CONTROL_AE_MODE_ON;
            break;
        case CONTROL_AE_MODE_ON:
            mCaptureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON);
            useFlashButton.setImageResource(R.drawable.flash_automatic);
            mFlashMode = CONTROL_AE_MODE_ON_AUTO_FLASH;
            break;
        case CONTROL_AE_MODE_ON_AUTO_FLASH:
            mCaptureRequestBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_OFF);
            useFlashButton.setImageResource(R.drawable.flash_off);
            mFlashMode = CONTROL_AE_MODE_OFF;
            break;
    }
}

所以我现在需要做的是根据选择的闪光灯模式，相机会适本地捕捉。目前无论我选择什么模式，都没有发生闪光。

我能做什么？

更多代码可以提供帮助。

       protected void onImageCaptureClick() {
        if (null == mCameraDevice) {
            Log.e(TAG, "cameraDevice is null");
            return;
        }
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);

        try {
            CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraDevice.getId());
            Size[] jpegSizes = null;
            if (characteristics != null) {
                jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP).getOutputSizes(ImageFormat.JPEG);
            }
            int width = 640;
            int height = 480;
            if (jpegSizes != null && 0 < jpegSizes.length) {
                width = jpegSizes[0].getWidth();
                height = jpegSizes[0].getHeight();
            }
            ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
            List<Surface> outputSurfaces = new ArrayList<>(2);
            outputSurfaces.add(reader.getSurface());
            outputSurfaces.add(new Surface(mTextureView.getSurfaceTexture()));
            final CaptureRequest.Builder captureBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
            captureBuilder.addTarget(reader.getSurface());
            // Use the same AE and AF modes as the preview.

            captureBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
            // Orientation
            int rotation = getWindowManager().getDefaultDisplay().getRotation();
            captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));

            final File file = new File(_pictureUri.getPath());
            ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
                @Override
                public void onImageAvailable(ImageReader reader) {
                    Image image = null;
                    try {
                        image = reader.acquireLatestImage();
                        ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                        byte[] bytes = new byte[buffer.capacity()];
                        buffer.get(bytes);
                        save(bytes);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (image != null) {
                            image.close();
                        }
                    }
                }


                private void save(byte[] bytes) throws IOException {
                    OutputStream output = null;
                    try {
                        output = new FileOutputStream(file);
                        output.write(bytes);
                    } finally {
                        if (null != output) {
                            output.close();
                        }
                    }
                }
            };
            reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
            final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
                //byte[] data;
                @Override
                public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
                    super.onCaptureCompleted(session, request, result);


                    Intent intent = new Intent (CameraActivity.this, CameraReviewPhotoActivity.class);
                    intent.putExtra (MediaStore.EXTRA_OUTPUT, _pictureUri);
                    startActivityForResult (intent, CameraActivity.kRequest_Code_Approve_Image);

                }
            };
            mCameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(CameraCaptureSession session) {
                    try {
                        session.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onConfigureFailed(CameraCaptureSession session) {
                }
            }, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }


    private void runPrecaptureSequence() {
    try {

        setFlash();
        mCaptureRequestBuilder.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
                CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);

        mState = STATE_WAITING_PRE_CAPTURE;
        mCameraCaptureSessions.capture(mCaptureRequestBuilder.build(), mCaptureCallback,
                mBackgroundHandler);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }

}

Answer 1

是的，它对我有用。这是我的代码:

public class AndroidCameraApi extends AppCompatActivity {
private static final String TAG = "AndroidCameraApi";
private Button takePictureButton;
private TextureView textureView;
private Button flashButton;
private CaptureRequest.Builder captureBuilder;
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
static {
    ORIENTATIONS.append(Surface.ROTATION_0, 90);
    ORIENTATIONS.append(Surface.ROTATION_90, 0);
    ORIENTATIONS.append(Surface.ROTATION_180, 270);
    ORIENTATIONS.append(Surface.ROTATION_270, 180);
}
private String cameraId;
protected CameraDevice cameraDevice;
protected CameraCaptureSession cameraCaptureSessions;
protected CaptureRequest captureRequest;
protected CaptureRequest.Builder captureRequestBuilder;
private Size imageDimension;
private ImageReader imageReader;
private File file;
private static final int REQUEST_CAMERA_PERMISSION = 200;
private boolean mFlashSupported;
private boolean flash_on=false;
private Handler mBackgroundHandler;
private HandlerThread mBackgroundThread;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    textureView = (TextureView) findViewById(R.id.texture);
    flashButton=(Button)findViewById(R.id.button);
    assert textureView != null;
    textureView.setSurfaceTextureListener(textureListener);
    takePictureButton = (Button) findViewById(R.id.btn_takepicture);
    assert takePictureButton != null;
    flashButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(!flash_on){

                    flash_on=true;


            }else{
                flash_on=false;



            }

        }
    });
    takePictureButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            takePicture();
        }
    });
}
TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
        //open your camera here
        openCamera();
    }
    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
        // Transform you image captured size according to the surface width and height
    }
    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
        return false;
    }
    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surface) {
    }
};
private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
    @Override
    public void onOpened(CameraDevice camera) {
        //This is called when the camera is open
        Log.e(TAG, "onOpened");
        cameraDevice = camera;
        createCameraPreview();
    }
    @Override
    public void onDisconnected(CameraDevice camera) {
        cameraDevice.close();
    }
    @Override
    public void onError(CameraDevice camera, int error) {
        cameraDevice.close();
        cameraDevice = null;
    }
};
final CameraCaptureSession.CaptureCallback captureCallbackListener = new CameraCaptureSession.CaptureCallback() {
    @Override
    public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
        super.onCaptureCompleted(session, request, result);
        Toast.makeText(AndroidCameraApi.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
        createCameraPreview();
    }
};
protected void startBackgroundThread() {
    mBackgroundThread = new HandlerThread("Camera Background");
    mBackgroundThread.start();
    mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
}
protected void stopBackgroundThread() {
    mBackgroundThread.quitSafely();
    try {
        mBackgroundThread.join();
        mBackgroundThread = null;
        mBackgroundHandler = null;
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}
protected void takePicture() {
    if(null == cameraDevice) {
        Log.e(TAG, "cameraDevice is null");
        return;
    }
    CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    try {
        CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraDevice.getId());
        Size[] jpegSizes = null;
        if (characteristics != null) {
            jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP).getOutputSizes(ImageFormat.JPEG);
        }
        int width = 640;
        int height = 480;
        if (jpegSizes != null && 0 < jpegSizes.length) {
            width = jpegSizes[0].getWidth();
            height = jpegSizes[0].getHeight();
        }
        ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
        List<Surface> outputSurfaces = new ArrayList<Surface>(2);
        outputSurfaces.add(reader.getSurface());
        outputSurfaces.add(new Surface(textureView.getSurfaceTexture()));
       captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
        captureBuilder.addTarget(reader.getSurface());

        //THIS YOU HAVE TO PUT YOUR METOD setFlash(); be shore your swith metos works i use just 2 states "Flash on" and "Flash off" you can add "Flash Auto"

        if(flash_on){
            captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON_ALWAYS_FLASH);
            captureBuilder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_SINGLE);
        }else{
            captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CameraMetadata.CONTROL_AE_MODE_ON);
            captureBuilder.set(CaptureRequest.FLASH_MODE, CameraMetadata.FLASH_MODE_OFF);
        }



        int rotation = getWindowManager().getDefaultDisplay().getRotation();
        captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));

        final File file = new File(Environment.getExternalStorageDirectory()+"/pic.jpg");
        ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
            @Override
            public void onImageAvailable(ImageReader reader) {
                Image image = null;
                try {
                    image = reader.acquireLatestImage();
                    ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                    byte[] bytes = new byte[buffer.capacity()];
                    buffer.get(bytes);
                    save(bytes);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (image != null) {
                        image.close();
                    }
                }
            }
            private void save(byte[] bytes) throws IOException {
                OutputStream output = null;
                try {
                    output = new FileOutputStream(file);
                    output.write(bytes);
                } finally {
                    if (null != output) {
                        output.close();
                    }
                }
            }
        };
        reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
        final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
            @Override
            public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
                super.onCaptureCompleted(session, request, result);
                Toast.makeText(AndroidCameraApi.this, "Saved:" + file, Toast.LENGTH_SHORT).show();
                createCameraPreview();
            }
        };
        cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback() {
            @Override
            public void onConfigured(CameraCaptureSession session) {
                try {
                    session.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
                } catch (CameraAccessException e) {
                    e.printStackTrace();
                }
            }
            @Override
            public void onConfigureFailed(CameraCaptureSession session) {
            }
        }, mBackgroundHandler);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}
protected void createCameraPreview() {
    try {
        SurfaceTexture texture = textureView.getSurfaceTexture();
        assert texture != null;
        texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
        Surface surface = new Surface(texture);
        captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
        captureRequestBuilder.addTarget(surface);
        cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback(){
            @Override
            public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                //The camera is already closed
                if (null == cameraDevice) {
                    return;
                }
                // When the session is ready, we start displaying the preview.
                cameraCaptureSessions = cameraCaptureSession;
                updatePreview();
            }
            @Override
            public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
                Toast.makeText(AndroidCameraApi.this, "Configuration change", Toast.LENGTH_SHORT).show();
            }
        }, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}
private void openCamera() {
    CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
    Log.e(TAG, "is camera open");
    try {
        cameraId = manager.getCameraIdList()[0];
        CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
        StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
        assert map != null;
        imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];
        // Add permission for camera and let user grant the permission
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(AndroidCameraApi.this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CAMERA_PERMISSION);
            return;
        }
        manager.openCamera(cameraId, stateCallback, null);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
    Log.e(TAG, "openCamera X");
}
public void updatePreview() {
    if(null == cameraDevice) {
        Log.e(TAG, "updatePreview error, return");
    }


    try {
        cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
    } catch (CameraAccessException e) {
        e.printStackTrace();
    }
}
private void closeCamera() {
    if (null != cameraDevice) {
        cameraDevice.close();
        cameraDevice = null;
    }
    if (null != imageReader) {
        imageReader.close();
        imageReader = null;
    }
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    if (requestCode == REQUEST_CAMERA_PERMISSION) {
        if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
            // close the app
            Toast.makeText(AndroidCameraApi.this, "Sorry!!!, you can't use this app without granting permission", Toast.LENGTH_LONG).show();
            finish();
        }
    }
}
@Override
protected void onResume() {
    super.onResume();
    Log.e(TAG, "onResume");
    startBackgroundThread();
    if (textureView.isAvailable()) {
        openCamera();
    } else {
        textureView.setSurfaceTextureListener(textureListener);
    }
}
@Override
protected void onPause() {
    Log.e(TAG, "onPause");
    //closeCamera();
    stopBackgroundThread();
    super.onPause();
}

@Override
protected void onDestroy() {
    closeCamera();
    super.onDestroy();
}

尝试一下，我会发现你的代码有什么问题 布局activity_main.xml: