羊皮书APP（Android版）开发系列（二十五）自动拍照保存照片－适用于Android 5.0 以下版本

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

<SurfaceView
        android:id="@+id/texture"
        android:layout_width="0.1dp"
        android:layout_height="0.1dp"
        android:layout_alignParentTop="true" />

    @Bind(R.id.texture)
    SurfaceView texture;
    private SurfaceHolder surfaceHolder;
    private Camera camera;
    
     private void initCamera() {
        surfaceHolder = texture.getHolder();

        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        surfaceHolder.addCallback(this);

    }

     @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        if (data != null) {
            Bitmap bitmap = Bytes2Bitmap(data);
            saveImageToGallery(getApplicationContext(), bitmap);
        }

        camera.startPreview();
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub

        int cameraNums = Camera.getNumberOfCameras();
        L.e("CAMERA_CONTROLL", cameraNums + "");
        try {
            //我的设备只有一个摄像头，故而直接使用，若为双摄像头，则需要设置使用的是前摄像头还是后摄像头
            camera = Camera.open(0);

        } catch (Exception e) {
            L.e("CAMERA_CONTROLL", e.getMessage());
        }
        try {
            camera.setPreviewDisplay(holder);
            Camera.Parameters parameters = camera.getParameters();
            parameters.set("orientation", "portrait");
            camera.setDisplayOrientation(90);
            parameters.setRotation(90);
            camera.setParameters(parameters);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            if (camera != null) {
                camera.release();
            }
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        if (camera != null) {
            camera.stopPreview();
            camera.release();
        }
    }

        camera.takePicture(null, null, StudentAttendanceActivity.this);

public Bitmap Bytes2Bitmap(byte[] b) {
        L.e("byte length", b.length + "");
        if (b.length != 0) {
            return BitmapFactory.decodeByteArray(b, 0, b.length);
        } else {
            return null;
        }
    }

    /**
     * 保存图片到本地
     *
     * @param context
     * @param bmp
     */
    public void saveImageToGallery(Context context, Bitmap bmp) {
        // 首先保存图片
        File appDir = new File(Environment.getExternalStorageDirectory(), AppConstants.FILEDIR);
        if (!appDir.exists()) {
            appDir.mkdir();
        }
        String fileName = dateStr + ".jpg";
        File file = new File(appDir, fileName);
        try {
            FileOutputStream fos = new FileOutputStream(file);
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, fos);
            fos.flush();
            fos.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        // 其次把文件插入到系统图库
        try {
            MediaStore.Images.Media.insertImage(context.getContentResolver(),
                    file.getAbsolutePath(), fileName, null);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        ButterKnife.unbind(this);
        if (camera!=null) {
            camera.release();
            camera = null;
        }
    }