一、自定义相机Camera，无API版本限制

（1）。实现接口 implements SurfaceHolder.Callback

private SurfaceView mView;private Camera mCamera;
private int cameraId = 0;//前置1、后置0

初期化Camera

    @Overridepublic void surfaceCreated(SurfaceHolder holder) {Camera.CameraInfo cameraInfo = new Camera.CameraInfo();for (int i = 0; i < Camera.getNumberOfCameras(); i++) {Camera.getCameraInfo(i, cameraInfo);if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {if (cameraId == 0) cameraId = i;}}mCamera = Camera.open(cameraId);mCamera.setDisplayOrientation(90);Camera.getCameraInfo(cameraId, cameraInfo);if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
//            mFaceView.setFront(true);}Log.i(TAG, "surfaceCreated");try {mCamera.setPreviewDisplay(mView.getHolder());} catch (Exception e) {Log.e(TAG, "Could not preview the image.", e);}}

（2）、布局layout.xml添加SurfaceView预览相机

<SurfaceViewandroid:id="@+id/surfaceview"android:layout_width="match_parent"android:layout_height="match_parent"android:layout_centerInParent="true"/>

mView = (SurfaceView) findViewById(R.id.surfaceview);

mCamera.setPreviewDisplay(mView.getHolder());

（3）、启动相机Camera类

private void startPreview() {if (mCamera != null) {Log.i(TAG, "startPreview0000");mCamera.startPreview();mCamera.setPreviewCallback(this);}
}

@Override
protected void onPostCreate(Bundle savedInstanceState) {super.onPostCreate(savedInstanceState);// Check for the camera permission before accessing the camera.  If the// permission is not granted yet, request permission.SurfaceHolder holder = mView.getHolder();holder.addCallback(this);holder.setFormat(ImageFormat.NV21);Log.i("lgq", "......onPostCreate");
}

（4）、点击拍照获取照片

创建回Camera调接口

    private Camera.PictureCallback mPicture = new Camera.PictureCallback() {@Overridepublic void onPictureTaken(byte[] data, Camera camera) {// 获取Jpeg图片，并保存在sd卡上
//            buff = data;bitmap = Bytes2Bimap(data);mHandler.sendEmptyMessageDelayed(REFRESH_COMPLETE, 0);}};

点击拍照

imageView.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {mCamera.autoFocus(new Camera.AutoFocusCallback() {@Overridepublic void onAutoFocus(boolean success, Camera camera) {// 从Camera捕获图片mCamera.takePicture(null, null, mPicture);}});}
});

二、.camera2.CameraDevice，TextureView实现自定义拍照。API=21以下的手机不可用，

（1）、layout.xml文件添加TextureView

<TextureViewandroid:id="@+id/tv_textview"android:layout_width="match_parent"android:layout_height="match_parent" />

实现代码比较长篇。。。。。。。。

demo链接：https://download.csdn.net/download/meixi_android/11168640

1、创建自定义遮罩层view

/*** 人脸检测区域View*/
public class FaceDetectRoundView extends View {private static final String TAG = FaceDetectRoundView.class.getSimpleName();public static final float SURFACE_HEIGHT = 1000f;public static final float SURFACE_RATIO = 0.75f;public static final float WIDTH_SPACE_RATIO = 0.33f;public static final float HEIGHT_RATIO = 0.1f;public static final float HEIGHT_EXT_RATIO = 0.2f;public static final int CIRCLE_SPACE = 5;public static final int PATH_SPACE = 16;public static final int PATH_SMALL_SPACE = 12;public static final int PATH_WIDTH = 4;public static final int COLOR_BG = Color.parseColor("#2F2F33");public static final int COLOR_RECT = Color.parseColor("#FFFFFF");public static final int COLOR_ROUND = Color.parseColor("#FFA800");private PathEffect mFaceRoundPathEffect = null;// new DashPathEffect(new float[]{PATH_SPACE, PATH_SPACE}, 1);private Paint mBGPaint;private Paint mPathPaint;private Paint mFaceRectPaint;private Paint mFaceRoundPaint;private Rect mFaceRect;private Rect mFaceDetectRect;private float mX;private float mY;private float mR;private boolean mIsDrawDash = true;public FaceDetectRoundView(Context context) {this(context, null);}public FaceDetectRoundView(Context context, AttributeSet attrs) {super(context, attrs);setLayerType(View.LAYER_TYPE_SOFTWARE, null);DisplayMetrics dm = context.getResources().getDisplayMetrics();float pathSpace = dip2px(context, PATH_SPACE);float pathSmallSpace = dip2px(context, PATH_SMALL_SPACE);float pathWidth = dip2px(context, PATH_WIDTH);mFaceRoundPathEffect = new DashPathEffect(new float[]{pathSpace, dm.heightPixels < SURFACE_HEIGHT? pathSmallSpace : pathSpace}, 1);mBGPaint = new Paint(Paint.ANTI_ALIAS_FLAG);mBGPaint.setColor(COLOR_BG);mBGPaint.setStyle(Paint.Style.FILL);mBGPaint.setAntiAlias(true);mBGPaint.setDither(true);mPathPaint = new Paint(Paint.ANTI_ALIAS_FLAG);mPathPaint.setColor(COLOR_ROUND);mPathPaint.setStrokeWidth(pathWidth);mPathPaint.setStyle(Paint.Style.STROKE);mPathPaint.setAntiAlias(true);mPathPaint.setDither(true);mFaceRectPaint = new Paint(Paint.ANTI_ALIAS_FLAG);mFaceRectPaint.setColor(COLOR_RECT);mFaceRectPaint.setStrokeWidth(pathWidth);mFaceRectPaint.setStyle(Paint.Style.STROKE);mFaceRectPaint.setAntiAlias(true);mFaceRectPaint.setDither(true);mFaceRoundPaint = new Paint(Paint.ANTI_ALIAS_FLAG);mFaceRoundPaint.setColor(COLOR_ROUND);mFaceRoundPaint.setStyle(Paint.Style.FILL);mFaceRoundPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));mFaceRoundPaint.setAntiAlias(true);mFaceRoundPaint.setDither(true);}

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2、添加自定义view方法

在activity中添加自定义遮罩层view即可实现

private FaceDetectRoundView mFaceView;

mFaceView = new FaceDetectRoundView(this);
mFaceView.setAlpha(0.43f);
addContentView(mFaceView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));