1. 程式人生 > >使用自定義Camera實現簡單拍照功能

使用自定義Camera實現簡單拍照功能

閒來無事,就把之前用自定義Camera實現的簡單拍照功能記錄一下。
Camera類在5.0以後不推薦使用了,取而代之的是android.hardware.camera2包下的類,本文使用Camera。
我們首先自定義一個View去繼承SurfaceView:

public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback, Camera.AutoFocusCallback {
    private SurfaceHolder mHolder;
    private Camera mCamera;
    private
static final int ORIENTATION = 90; private int mScreenWidth; private int mScreenHeight; private boolean isOpen; public CameraSurfaceView(Context context, AttributeSet attrs) { super(context, attrs); getScreenMatrix(context); mHolder = getHolder(); mHolder.addCallback(this
); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } private void getScreenMatrix(Context context) { WindowManager WM = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); DisplayMetrics outMetrics = new DisplayMetrics(); WM.getDefaultDisplay().getMetrics(outMetrics); mScreenWidth = outMetrics.widthPixels; mScreenHeight = outMetrics.heightPixels; } public
void takePicture(Camera.ShutterCallback mShutterCallback, Camera.PictureCallback rawPictureCallback, Camera.PictureCallback jpegPictureCallback) { if (mCamera != null) mCamera.takePicture(mShutterCallback, rawPictureCallback, jpegPictureCallback); } public void startPreview() { mCamera.startPreview(); } @Override public void surfaceCreated(SurfaceHolder holder) { if (!checkCameraHardware(getContext())) return; if (mCamera == null) { isOpen = safeCameraOpen(Camera.CameraInfo.CAMERA_FACING_BACK); } if (!isOpen) { return; } mCamera.setDisplayOrientation(ORIENTATION); try { mCamera.setPreviewDisplay(holder); } catch (IOException e) { e.printStackTrace(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { if (mCamera != null) { setCameraParams(mScreenWidth, mScreenHeight); mCamera.startPreview(); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { releaseCameraAndPreview(); } private boolean safeCameraOpen(int id) { boolean qOpened = false; try { releaseCameraAndPreview(); mCamera = Camera.open(id); qOpened = (mCamera != null); } catch (Exception e) { e.printStackTrace(); } return qOpened; } private void releaseCameraAndPreview() { if (mCamera != null) { mCamera.stopPreview(); mCamera.release(); mCamera = null; } } private boolean checkCameraHardware(Context context) { if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) { return true; } else { return false; } } @Override public void onAutoFocus(boolean success, Camera camera) { } private void setCameraParams(int width, int height) { Camera.Parameters parameters = mCamera.getParameters(); // 獲取攝像頭支援的PictureSize列表 List<Camera.Size> pictureSizeList = parameters.getSupportedPictureSizes(); /**從列表中選取合適的解析度*/ Camera.Size picSize = getProperSize(pictureSizeList, ((float) height / width)); if (null == picSize) { picSize = parameters.getPictureSize(); } // 根據選出的PictureSize重新設定SurfaceView大小 float w = picSize.width; float h = picSize.height; parameters.setPictureSize(picSize.width, picSize.height); this.setLayoutParams(new RelativeLayout.LayoutParams((int) (height * (h / w)), height)); // 獲取攝像頭支援的PreviewSize列表 List<Camera.Size> previewSizeList = parameters.getSupportedPreviewSizes(); Camera.Size preSize = getProperSize(previewSizeList, ((float) height) / width); if (null != preSize) { parameters.setPreviewSize(preSize.width, preSize.height); } parameters.setJpegQuality(100); // 設定照片質量 if (parameters.getSupportedFocusModes().contains(android.hardware.Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) { parameters.setFocusMode(android.hardware.Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);// 連續對焦模式 } mCamera.setDisplayOrientation(90);// 設定PreviewDisplay的方向,效果就是將捕獲的畫面旋轉多少度顯示 mCamera.setParameters(parameters); } /** * 選取合適的解析度 */ private Camera.Size getProperSize(List<Camera.Size> pictureSizeList, float screenRatio) { Camera.Size result = null; for (Camera.Size size : pictureSizeList) { float currentRatio = ((float) size.width) / size.height; if (currentRatio - screenRatio == 0) { result = size; break; } } if (null == result) { for (Camera.Size size : pictureSizeList) { float curRatio = ((float) size.width) / size.height; if (curRatio == 4f / 3) {// 預設w:h = 4:3 result = size; break; } } } return result; } }

程式碼沒什麼難度,在View建立的時候完成Camera的初始化,然後對Camera進行引數的設定(圖片尺寸,質量之類的),最後別忘了在View銷燬的時候對資源進行釋放。

控制元件定義完了之後我們就要去使用它,在佈局檔案中新增就OK:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <com.padoon.cameratest.CameraSurfaceView
        android:id="@+id/sv_camera"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="4"/>

    <ImageView
        android:id="@+id/img_take_photo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_gravity="bottom"
        android:layout_marginBottom="10dp"
        android:layout_marginRight="10dp"
        android:src="@mipmap/icon_camera"/>
</RelativeLayout>

然後在Activity中去完成拍照功能:

public class CameraActivity extends AppCompatActivity {
    private boolean isClick = true;
    private static final String PATH_IMAGES = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "easy_check";
    private CameraSurfaceView mCameraSurfaceView;
    //拍照快門的回撥
    private Camera.ShutterCallback mShutterCallback = new Camera.ShutterCallback() {
        @Override
        public void onShutter() {

        }
    };
    //拍照完成之後返回原始資料的回撥
    private Camera.PictureCallback rawPictureCallback = new Camera.PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {

        }
    };
    //拍照完成之後返回壓縮資料的回撥
    private Camera.PictureCallback jpegPictureCallback = new Camera.PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            mCameraSurfaceView.startPreview();
            saveFile(data);
            Toast.makeText(CameraActivity.this, "拍照成功", Toast.LENGTH_SHORT).show();
            isClick = true;

        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageView img_take_photo = (ImageView) findViewById(R.id.img_take_photo);
        mCameraSurfaceView = (CameraSurfaceView) findViewById(R.id.sv_camera);
        img_take_photo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                takePhoto();
            }
        });
    }

    public void takePhoto() {
        if (isClick) {
            isClick = false;
            mCameraSurfaceView.takePicture(mShutterCallback, rawPictureCallback, jpegPictureCallback);
        }
    }
    //儲存圖片到硬碟
    public void saveFile(byte[] data) {
        String fileName = UUID.randomUUID().toString() + ".jpg";
        FileOutputStream outputStream = null;
        try {
            File file = new File(PATH_IMAGES);
            if (!file.exists()) {
                file.mkdirs();
            }
            outputStream = new FileOutputStream(PATH_IMAGES + File.separator + fileName);
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
            bufferedOutputStream.write(data, 0, data.length);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

最後記得新增拍照跟磁碟操作許可權:

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

到這一個非常簡單的拍照Demo就完成了,只能當做Demo使用,離開發正式使用還有一段的距離,再次特地記錄一下。

原始碼