Nexus
Nexus携帯原生AndroidシステムAndroid 8.0

に質問

テストではNexus携帯電話、android 8.0携帯電話では、スキャン時に表示される写真のプレビュー方向が正しくなく、180度回転して変形していることが分かった.しかし、他の携帯電話やシステムでテストするのは問題ありません.

解決する

相変わらずStack Overflowですね.親測はこの問題を完璧に解決した.

private void surfaceIsChanged() {
        if (mHolder.getSurface() == null) {
            System.out.println("getSurface,nullnull");
            return;
        }
        try {
            mCamera.stopPreview();
        } catch (Exception e) {
        }
        try {
            Camera.Size previewSize = mCamera.getParameters().getPreviewSize();
            int dataBufferSize = (int) (previewSize.height * previewSize.width * (ImageFormat.getBitsPerPixel(mCamera.getParameters()
                    .getPreviewFormat()) / 8.0));
            mCamera.addCallbackBuffer(new byte[dataBufferSize]);
            mCamera.setPreviewDisplay(mHolder);
            mCamera.setPreviewCallbackWithBuffer(previewCallback);
            mCamera.startPreview();
            mCamera.autoFocus(autoFocusCallback);


            Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
            int camIdx = 0; // DO your logic to get front or back camera...or loop through all avaialable.
            Camera.getCameraInfo(camIdx, cameraInfo);

            try {
                // If using back camera then simply rotate what CameraInfo tells you.
                if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK)
                    mCamera.setDisplayOrientation(cameraInfo.orientation);
                else
                    // If using front camera note that image might be flipped to give users the impresion the are looking at a mirror.
                    mCamera.setDisplayOrientation( (360 - cameraInfo.orientation) % 360);
            } catch (Exception e) {
                e.printStackTrace();
            }

            // Toast.makeText(QRZbarActivity.this, " ",
            // Toast.LENGTH_SHORT).show();
            autoOpenLight();
        } catch (Exception e) {
            Toast.makeText(BaseScanActivity.this, R.string.account_toast_not_open_camera, Toast.LENGTH_SHORT).show();
//          showTip(" " + getResources().getString(R.string.app_name) + " 
 “  - ” ");
            Log.d("DBG", "Error starting camera preview: " + e.getMessage());
        }
    }

主に有効なコードは次のとおりです.

Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
            int camIdx = 0; // DO your logic to get front or back camera...or loop through all avaialable.
            Camera.getCameraInfo(camIdx, cameraInfo);

            try {
                // If using back camera then simply rotate what CameraInfo tells you.
                if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK)
                    mCamera.setDisplayOrientation(cameraInfo.orientation);
                else
                    // If using front camera note that image might be flipped to give users the impresion the are looking at a mirror.
                    mCamera.setDisplayOrientation( (360 - cameraInfo.orientation) % 360);
            } catch (Exception e) {
                e.printStackTrace();
            }

写真の内容に応じて表示方向を設定します.
参考:解決方法
//END 2018年4月19日