代码目录结构
LAUNCHER activity：CameraActivity ：
onCreate()方法中创建Camera工具类CameraHelper的实例并初始化：
mCameraHelper = new CameraHelper(mActivity, textureView, btnImagePreview);
重写onClick方法监听拍照点击事件：
mCameraHelper.takePicture();
CameraHelper类中实现相机的预览与拍照，流程如下：
大致流程如下：
用CameraManager的openCamera(String cameraId, CameraDevice.StateCallback callback, Handler handler)方法打开指定摄像头。该方法的第一个参数代表要打开的摄像头ID；第二个参数用于监听摄像头的状态；第三个参数代表执行callback的Handler，如果程序希望直接在当前线程中执行callback，则可将handler参数设为null。 当摄像头被打开之后会回调接口mStateCallback.onOpened，程序即可获取CameraDevice —— 即根据摄像头ID获取了指定摄像头设备，然后调用CameraDevice的createCaptureSession(List outputs, CameraCaptureSession. StateCallback callback，Handler handler)方法来创建CameraCaptureSession。该方法的第一个参数是一个List集合，封装了所有需要从该摄像头获取图片的Surface，第二个参数用于监听CameraCaptureSession的创建过程；第三个参数代表执行callback的Handler，如果程序希望直接在当前线程中执行callback，则可将handler参数设为null。 不管预览还是拍照，程序都调用CameraDevice的createCaptureRequest(int templateType)方法创建CaptureRequest.Builder，该方法支持TEMPLATE_PREVIEW（预览）、TEMPLATE_RECORD（拍摄视频）、TEMPLATE_STILL_CAPTURE（拍照）等参数。 通过第3步所调用方法返回的CaptureRequest.Builder设置拍照的各种参数，比如对焦模式、曝光模式等。 调用CaptureRequest.Builder的build()方法即可得到CaptureRequest对象，接下来程序可通过CameraCaptureSession的setRepeatingRequest()方法开始预览，或调用capture()方法拍照。
相机的预览与拍照流程我们基本了解了。 预览时，是将mSurfaceHolder.getSurface()作为目标，使用setRepeatingRequest()方法，
显示拍照结果时，是将mImageReader.getSurface()作为目标，使用capture()方法
layout布局如下：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="/apk/res/android"xmlns:app="/apk/res-auto"xmlns:tools="/tools"android:layout_width="wrap_content"android:layout_height="wrap_content"android:id="@+id/relativeLayout"android:orientation="vertical"android:background="#000"><ImageViewandroid:id="@+id/imageView"android:layout_width="match_parent"android:layout_height="112dp"android:background="@color/black"/><LinearLayoutandroid:id="@+id/linearLayout"android:layout_width="match_parent"android:layout_height="208dp"android:layout_alignParentBottom="true"android:orientation="vertical"><com.bilibili.camera2.view.SideBarandroid:id="@+id/sideBar"android:layout_width="300dp"android:layout_height="60dp"android:visibility="gone"android:layout_marginTop="10dp"android:layout_gravity="center_horizontal"/><com.bilibili.camera2.view.HorizontalSelectedViewandroid:id="@+id/selectedView"android:layout_width="match_parent"android:layout_marginTop="10dp"android:layout_height="60dp"android:layout_gravity="center_horizontal"app:HorizontalSelectedViewSeeSize="5"android:visibility="visible"app:HorizontalSelectedViewSelectedTextColor="@color/white"app:HorizontalSelectedViewSelectedTextSize="40"app:HorizontalSelectedViewTextColor="@color/gray"app:HorizontalSelectedViewTextSize="30" /><RelativeLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"><!-- 拍照按钮 --><ImageButtonandroid:id="@+id/btnTakePicture"android:layout_width="80dp"android:layout_height="80dp"android:layout_centerHorizontal="true"android:background="@drawable/ic_camera_main_btn_01_auto"android:layout_gravity="center"tools:ignore="ContentDescription" /><ImageViewandroid:id="@+id/faceBackCameraChange"android:layout_width="70dp"android:layout_height="70dp"android:layout_marginStart="280dp"android:layout_centerVertical="true"android:background="@drawable/ic_camera_main_btn_02_switch"android:clickable="true"tools:ignore="ContentDescription" /></RelativeLayout></LinearLayout><LinearLayoutandroid:id="@+id/linearLayoutBottom"android:layout_width="match_parent"android:layout_height="48dp"android:background="@color/black"android:layout_alignParentBottom="true"android:orientation="horizontal" /></RelativeLayout>
CameraHelper主要逻辑代码如下：
class CameraHelper {private final Activity mActivity;private final TextureView mTextureView;private static final String TAG = "CameraHelper";private static final int PREVIEW_WIDTH = 1080; //预览的宽度private static final int PREVIEW_HEIGHT = 2340;//预览的高度private static final int SAVE_WIDTH = 1080;//保存图片的宽度private static final int SAVE_HEIGHT = 23400; //保存图片的高度private static final int PREVIEW_FIRST_GET_IMAGE = 0;private CameraManager mCameraManager;private ImageReader mImageReader;private CameraDevice mCameraDevice;private CameraCaptureSession mCameraCaptureSession;private CircleImageView imageButton;private String mCameraId = "0";private CameraCharacteristics mCameraCharacteristics;private int mCameraSensorOrientation = 0; //摄像头方向private int mCameraFacing = CameraCharacteristics.LENS_FACING_BACK;//默认使用后置摄像头//private int mDisplayRotation = mActivity.getWindowManager().getDefaultDisplay().getRotation();//手机方向private boolean canTakePicture = true; //是否可以拍照private boolean canExchangeCamera = false;//是否可以切换摄像头private Handler mCameraHandler;private HandlerThread handlerThread = new HandlerThread("CameraThread");private Size mPreviewSize = new Size(PREVIEW_WIDTH, PREVIEW_HEIGHT); //预览大小private Size mSavePicSize = new Size(SAVE_WIDTH, SAVE_HEIGHT); //保存图片大小private CoordinateTransformer mTransformer;private int i = 0;public CameraHelper(Activity mActivity, TextureView mTextureView, CircleImageView imageButton) {this.mActivity = mActivity;this.mTextureView = mTextureView;this.imageButton = imageButton;init();}private void init() {handlerThread.start();mCameraHandler = new Handler(Looper.myLooper());mTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {@Overridepublic void onSurfaceTextureAvailable(@NonNull SurfaceTexture surface, int width, int height) {initCameraInfo();}@Overridepublic boolean onSurfaceTextureDestroyed(@NonNull SurfaceTexture surface) {releaseCamera();return true;}@Overridepublic void onSurfaceTextureSizeChanged(@NonNull SurfaceTexture surface, int width, int height) {}@Overridepublic void onSurfaceTextureUpdated(@NonNull SurfaceTexture surface) {}});}public CameraDevice getCameraDevice(){Log.d(TAG, "getCameraDevice: mCameraDevice : " + mCameraDevice);return mCameraDevice;}public void releaseCamera() {if (mCameraCaptureSession != null) {mCameraCaptureSession.close();mCameraCaptureSession = null;}if (mCameraDevice != null){mCameraDevice.close();mCameraDevice = null;}if (mImageReader != null){mImageReader.close();mImageReader = null;}canExchangeCamera = false;}public void releaseThread() {handlerThread.quitSafely();mCameraHandler = null;}/*** 拍照*/public void takePicture(){Log.i(TAG, "takePicture: 进行拍照 1");if (mCameraDevice == null || !canTakePicture || ! mTextureView.isAvailable()) {Log.d(TAG, "takePicture: 进行拍照 error 退出");return;}try {CaptureRequest.Builder captureBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);captureBuilder.addTarget(mImageReader.getSurface());captureBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, mCameraSensorOrientation);mCameraCaptureSession.capture(captureBuilder.build(),null, mCameraHandler);Thread.sleep(200);Log.i(TAG, "takePicture: picture capture finish");} catch (CameraAccessException | InterruptedException e) {e.printStackTrace();}}/*** 切换摄像头*/public void exchangeCamera(){if (mCameraDevice == null || !canExchangeCamera || !mTextureView.isAvailable()) return;mCameraFacing = (mCameraFacing == CameraCharacteristics.LENS_FACING_FRONT)? CameraCharacteristics.LENS_FACING_BACK : CameraCharacteristics.LENS_FACING_FRONT;mPreviewSize = new Size(PREVIEW_WIDTH, PREVIEW_HEIGHT);//重置预览大小releaseCamera();initCameraInfo();}/*** 初始化*/@SuppressLint("ShowToast")private void initCameraInfo() {try {mCameraManager = (CameraManager) mActivity.getSystemService(Context.CAMERA_SERVICE);String[] cameraIdList = mCameraManager.getCameraIdList();if (cameraIdList == null) {Toast.makeText(mActivity, "没有相机可用", Toast.LENGTH_SHORT);return;}for (String id : cameraIdList) {CameraCharacteristics cameraCharacteristics = mCameraManager.getCameraCharacteristics(id);//+Type add focusRectF mPreviewRect = new RectF(0,0,1080, 1440);mTransformer = new CoordinateTransformer(cameraCharacteristics, mPreviewRect);Rect mFocusRect = new Rect();RectF rectF = mTransformer.toCameraSpace(mPreviewRect);mFocusRect.left = Math.round(rectF.left);mFocusRect.top = Math.round(rectF.top);mFocusRect.right = Math.round(rectF.right);mFocusRect.bottom = Math.round(rectF.bottom);//MeteringRectangle meteringRectangle = new MeteringRectangle(mFocusRect,1000);//-Type add focusInteger facing = cameraCharacteristics.get(CameraCharacteristics.LENS_FACING);if (facing == mCameraFacing) {mCameraId = id;mCameraCharacteristics = cameraCharacteristics;}Log.i(TAG, "initCameraInfo: 设备中的摄像头: " + id);}Integer supportLevel = mCameraCharacteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);if (supportLevel == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) {Toast.makeText(mActivity, "相机硬件不支持新特性", Toast.LENGTH_SHORT);}//获取摄像头方向mCameraSensorOrientation = mCameraCharacteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);//获取StreamConfigurationMap，它是管理摄像头支持的所有输出格式和尺寸StreamConfigurationMap configurationMap = mCameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);Size[] savePicSizes = configurationMap.getOutputSizes(ImageFormat.JPEG); //保存照片尺寸if (savePicSizes == null) {Log.d(TAG, "initCameraInfo: savePicSizes为空");return;}Size[] previewSizes = configurationMap.getOutputSizes(SurfaceTexture.class); //预览尺寸if (previewSizes == null) {Log.d(TAG, "initCameraInfo: previewSizes为空");return;}int mDisplayRotation = mActivity.getWindowManager().getDefaultDisplay().getRotation();//手机方向boolean exchange = exchangeWidthAndHeight(mDisplayRotation, mCameraSensorOrientation);if (exchange) {mSavePicSize = getBestSize(mSavePicSize.getHeight(),mSavePicSize.getWidth(),mSavePicSize.getHeight(),mSavePicSize.getWidth(),Arrays.asList(savePicSizes));} else {mSavePicSize = getBestSize(mSavePicSize.getWidth(),mSavePicSize.getHeight(),mSavePicSize.getWidth(),mSavePicSize.getHeight(),Arrays.asList(savePicSizes));}if (exchange) {mPreviewSize = getBestSize(mPreviewSize.getHeight(),mPreviewSize.getWidth(),mTextureView.getHeight(),mTextureView.getWidth(),Arrays.asList(previewSizes));} else {mPreviewSize = getBestSize(mPreviewSize.getWidth(),mPreviewSize.getHeight(),mTextureView.getWidth(),mTextureView.getHeight(),Arrays.asList(previewSizes));}mPreviewSize = new Size(1080,1440);if (mTextureView.getSurfaceTexture() == null){Log.i(TAG, "initCameraInfo: mTextureView.getSurfaceTexture() 执行了*******************");SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();surfaceTexture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());mTextureView.setSurfaceTexture(surfaceTexture);}Log.d(TAG, "预览最优尺寸: " + mPreviewSize.getWidth() + " " + mPreviewSize.getHeight() +"比例 " + mPreviewSize.getWidth() / mPreviewSize.getHeight());Log.d(TAG, "保存图片最优尺寸: " + mSavePicSize.getWidth() + " " + mSavePicSize.getHeight() +"比例 " + mSavePicSize.getWidth() / mSavePicSize.getHeight());mImageReader = ImageReader.newInstance(mSavePicSize.getWidth(), mSavePicSize.getHeight(), ImageFormat.JPEG, 1);mImageReader.setOnImageAvailableListener(onImageAvailableListener, mCameraHandler);Log.d(TAG, "initCameraInfo: mTextureView-----------5");openCamera();} catch (CameraAccessException e) {e.printStackTrace();}}/*** 打开相机*/private void openCamera() {if (ActivityCompat.checkSelfPermission(mActivity, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {// TODO: Consider calling// ActivityCompat#requestPermissions// here to request the missing permissions, and then overriding// public void onRequestPermissionsResult(int requestCode, String[] permissions,// int[] grantResults)// to handle the case where the user grants the permission. See the documentation// for ActivityCompat#requestPermissions for more details.Log.d(TAG, "initCameraInfo: mTextureView-----------没有相机权限");List<String> permissionList = new ArrayList<>();permissionList.add(Manifest.permission.READ_EXTERNAL_STORAGE);permissionList.add(Manifest.permission.CAMERA);permissionList.add(Manifest.permission.CALL_PHONE);permissionList.add(Manifest.permission.MODIFY_AUDIO_SETTINGS);permissionList.add(Manifest.permission.ACCESS_BACKGROUND_LOCATION);permissionList.add(Manifest.permission.READ_PHONE_STATE);permissionList.add(Manifest.permission.INTERNET);permissionList.add(Manifest.permission.VIBRATE);permissionList.add(Manifest.permission.ACCESS_WIFI_STATE);ActivityCompat.requestPermissions(mActivity, permissionList.toArray(new String[permissionList.size()]),1002);}else {try {Log.d(TAG, "initCameraInfo: mTextureView-----------6准备打开相机");mCameraManager.openCamera(mCameraId, mStateCallback, mCameraHandler);Log.d(TAG, "openCamera: 打开相机");} catch (CameraAccessException e) {e.printStackTrace();}}}private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {@Overridepublic void onOpened(@NonNull CameraDevice camera) {Log.i(TAG, "onOpened: ");mCameraDevice = camera;createCaptureSession(mCameraDevice);}@Overridepublic void onDisconnected(@NonNull CameraDevice camera) {Log.i(TAG, "onDisconnected: ");}@Overridepublic void onError(@NonNull CameraDevice camera, int error) {Log.i(TAG, "onError: ");Toast.makeText(mActivity, "打开相机失败！error: " + error, Toast.LENGTH_SHORT);}};private void createCaptureSession(CameraDevice cameraDevice){try {Log.d(TAG, "createCaptureSession的CameraDevice ：" + cameraDevice);CaptureRequest.Builder builder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);@SuppressLint("Recycle")Surface surface = new Surface(mTextureView.getSurfaceTexture());builder.addTarget(surface);builder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);builder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);List<Surface> list = new ArrayList<>();list.add(surface);list.add(mImageReader.getSurface());cameraDevice.createCaptureSession(list, new CameraCaptureSession.StateCallback() {@Overridepublic void onConfigured(@NonNull CameraCaptureSession session) {mCameraCaptureSession = session;try {session.setRepeatingRequest(builder.build(), mCaptureCallback, mCameraHandler );} catch (CameraAccessException e) {e.printStackTrace();}}@Overridepublic void onConfigureFailed(@NonNull CameraCaptureSession session) {Log.d(TAG, "onConfigureFailed: 开启预览会话失败");}}, mCameraHandler);} catch (CameraAccessException e) {e.printStackTrace();}}private CameraCaptureSession.CaptureCallback mCaptureCallback = new CameraCaptureSession.CaptureCallback() {@Overridepublic void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {super.onCaptureCompleted(session, request, result);canExchangeCamera = true;canTakePicture = true;}@SuppressLint("ShowToast")@Overridepublic void onCaptureFailed(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull CaptureFailure failure) {super.onCaptureFailed(session, request, failure);Log.d(TAG, "onCaptureFailed");Toast.makeText(mActivity,"开启预览失败",Toast.LENGTH_SHORT);}};private final ImageReader.OnImageAvailableListener onImageAvailableListener = reader -> {Image image = reader.acquireLatestImage();ByteBuffer byteBuffer = image.getPlanes()[0].getBuffer();byte[] bytesArray = new byte[byteBuffer.remaining()];byteBuffer.get(bytesArray);image.close();String localPicturePath = BitmapUtils.savePicture(bytesArray, "Camera");if (localPicturePath.equals("")){Log.d(TAG, "没有获取到最后一张图片的路径！！！！！: " + localPicturePath);imageButton.setImageResource(PREVIEW_FIRST_GET_IMAGE);}else {Bitmap bitmap = BitmapFactory.decodeFile(localPicturePath);int width = bitmap.getWidth();int height = bitmap.getHeight();float w = (float) 256 / width;//float h = (float) 256 / height;Matrix matrix = new Matrix();matrix.postScale(w, w);Bitmap newBitmap1 = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);Matrix matrix1 = new Matrix();matrix1.setRotate(90f);Bitmap resultBitmap = Bitmap.createBitmap(newBitmap1, 0, 0, newBitmap1.getWidth(), newBitmap1.getHeight(), matrix1, true);imageButton.setImageBitmap(resultBitmap);Log.d(TAG, "onImageAvailable: ------------------------------------------------------------图片保存");}};private class CompareSizeByArea implements Comparator<Size> {@Overridepublic int compare(Size size1, Size size2) {return (int) Math.signum( size1.getWidth() * size1.getHeight() - size2.getWidth() * size2.getHeight());}}/*** 根据提供的屏幕方向 [displayRotation] 和相机方向 [sensorOrientation] 返回是否需要交换宽高*/private boolean exchangeWidthAndHeight(int displayRotation, int sensorOrientation){boolean exchange = false;switch (displayRotation){case Surface.ROTATION_0:case Surface.ROTATION_180:if (sensorOrientation == 90 || sensorOrientation == 270){exchange = true;}break;case Surface.ROTATION_90:case Surface.ROTATION_270:if (sensorOrientation == 0 || sensorOrientation == 180){exchange = true;}break;}Log.i(TAG, "屏幕方向: " + displayRotation);Log.i(TAG, "相机方向: " + sensorOrientation);return exchange;}}
TION_180:
if (sensorOrientation == 90 || sensorOrientation == 270){
exchange = true;
}
break;
case Surface.ROTATION_90:
case Surface.ROTATION_270:if (sensorOrientation == 0 || sensorOrientation == 180){exchange = true;}break;}Log.i(TAG, "屏幕方向: " + displayRotation);Log.i(TAG, "相机方向: " + sensorOrientation);return exchange;}
}
