我是变焦相机api 2的代码应用程序。但是当我触摸设备时我可以变焦相机

Question

我从gifhub相机2Bacsic master加载代码。我添加变焦camera2的代码，但我不工作。请有人帮助我。 这是我的代码。

这是变焦相机api 2的值

 protected CameraCharacteristics cameraCharacteristics;
    protected CameraCaptureSession captureSession;
    protected CaptureRequest.Builder previewRequestBuilder;

    //Zooming
    protected float fingerSpacing = 0;
    protected double zoom_level = 1;
    protected float maximumZoomLevel;
    protected Rect zoom;

//这是代码CaptureStillPicture

private void captureStillPicture() {
        try {
            final Activity activity = getActivity();
            if (null == activity || null == mCameraDevice) {
                return;
            }
            // This is the CaptureRequest.Builder that we use to take a picture.
            final CaptureRequest.Builder captureBuilder =
                    mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
            captureBuilder.addTarget(mImageReader.getSurface());

            // Use the same AE and AF modes as the preview.
            captureBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
            if (zoom != null) {
                captureBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
            }
            setAutoFlash(captureBuilder);

            // Orientation
            int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
            captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, getOrientation(rotation));

            CameraCaptureSession.CaptureCallback CaptureCallback
                    = new CameraCaptureSession.CaptureCallback() {

                @Override
                public void onCaptureCompleted(@NonNull CameraCaptureSession session,
                                               @NonNull CaptureRequest request,
                                               @NonNull TotalCaptureResult result) {
                    showToast("Saved: " + mFile);
                    Log.d(TAG, mFile.toString());
                    unlockFocus();
                }
            };
            mCaptureSession.stopRepeating();
            mCaptureSession.abortCaptures();
            mCaptureSession.capture(captureBuilder.build(), CaptureCallback, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

这是课堂onTouchCamera。我从gifhub相机2Bacsic master加载代码。我添加缩放相机2的代码，但我不工作

 public boolean onTouch(View v, MotionEvent event) {
        try {
            CameraManager manager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE );
            CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraId);

            float maxZoom = (characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM))*10;

            Rect m = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
            int action = event.getAction();
            float current_finger_spacing;

            if (event.getPointerCount() > 1) {
                // Multi touch logic
                current_finger_spacing = getFingerSpacing(event);

                if(fingerSpacing != 0){
                    if(current_finger_spacing > fingerSpacing && maxZoom > zoom_level){
                        zoom_level = zoom_level + 0.4;
                        //zoom_level++;
                    } else if (current_finger_spacing < fingerSpacing && zoom_level > 1) {
                        zoom_level = zoom_level - .4;
                        //zoom_level--;

                    }
                    int minW = (int) (m.width() / maxZoom);
                    int minH = (int) (m.height() / maxZoom);
                    int difW = m.width() - minW;
                    int difH = m.height() - minH;
                    int cropW = difW /100 *(int)zoom_level;
                    int cropH = difH /100 *(int)zoom_level;
                    cropW -= cropW & 3;
                    cropH -= cropH & 3;
                    Rect zoom = new Rect(cropW, cropH, m.width() - cropW, m.height() - cropH);
                    mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
                }
                fingerSpacing = current_finger_spacing;
            }
            else{
                if (action == MotionEvent.ACTION_UP) {
                    //single touch logic
                }
            }

            try {
                mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback,
                        null);
            }
            catch (CameraAccessException e) {
                e.printStackTrace();
            }
            catch (NullPointerException ex)
            {
                ex.printStackTrace();
            }
        }
        catch (CameraAccessException e)
        {
            throw new RuntimeException("can not access camera.", e);
        }

        return true;
    }

class fingercamera

 private float getFingerSpacing(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        return (float) Math.sqrt(x * x + y * y);
    }