CameraX - 在纵向模式下锁定活动时仅旋转预览

Question

1. 设置 -> 手机固定在支架上，不能旋转。相机正对着笔记本

2. MyCameraActivity -> 固定方向 -> 纵向

3. 用户应该能够在点击按钮时旋转预览，即我的预览应该被旋转（例如，如果我在开始时看到向上箭头，那么点击用户应该能够向右箭头）

我可以在 camera2 中执行此操作，但找不到任何有关 cameraX 的有用信息。

Answer 1

CameraX' PreviewView 现在支持该功能。使用 PreviewView，您只需将预览置于COMPATIBLE 模式即可旋转预览，然后设置预览的目标旋转。

代码示例：

previewView.setImplementationMode(COMPATIBLE)
preview.setTargetRotation(ROTATION_0)

Answer 2

解决 camerax 版本 1.0.0-alpha2

1. 在更新变换中设置矩阵。
2. 旋转 textview 以旋转预览

Camera2 api 也可以应用类似的逻辑（为我工作）

private Preview setPreview() {

        PreviewConfig pConfig = new PreviewConfig.Builder()
                .setLensFacing(CameraX.LensFacing.BACK)
                .build();
        Preview preview = new Preview(pConfig);

        preview.setOnPreviewOutputUpdateListener(
                output -> {
                    ViewGroup parent = (ViewGroup) binding.viewFinder.getParent();
                    parent.removeView(binding.viewFinder);
                    parent.addView(binding.viewFinder, 0);
                    binding.viewFinder.setSurfaceTexture(output.getSurfaceTexture());
                    updateTransform();
                });

        return preview;
    }


    private void updateTransform() {
        float viewWidth = binding.viewFinder.getMeasuredWidth();
        float viewHeight = binding.viewFinder.getMeasuredHeight();
         Size mPreviewSize = new Size(1080,720);

        Activity activity = getActivity();
        if (null == binding.viewFinder || null == mPreviewSize || null == activity) {
            return;
        }
        int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(90 * (rotation - 2), centerX, centerY);
        } else if (Surface.ROTATION_180 == rotation) {
            matrix.postRotate(180, centerX, centerY);
        }
        binding.viewFinder.setTransform(matrix);
    }
    int rotatiion = 0;
    private void setRotationClickListener() {

        binding.captureButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (rotatiion == 0) {
                    rotatiion = 90;
                    binding.viewFinder.setRotation(90);
                }else if(rotatiion == 90) {
                    rotatiion = 180;
                    binding.viewFinder.setRotation(180);
                }else if(rotatiion == 180) {
                    rotatiion = 270;
                    binding.viewFinder.setRotation(270);
                }else if(rotatiion == 270) {
                    rotatiion = 0;
                    binding.viewFinder.setRotation(0);
                }
            }
        });
    }