从相机拍摄的图像旋转

Question

在我的应用程序中，用户从相机捕获图像或从图库中选择图像，然后将其转换为pdf并上载到服务器，现在我的问题是，从相机捕获的图像在某些设备上旋转，我有代码尝试解决此问题，但它不起作用

 private void PDFCreation(){
        PdfDocument document=new PdfDocument();
        PdfDocument.PageInfo pageInfo;
        PdfDocument.Page page;
        Canvas canvas;
        int i;
        for (i=0; i < list.size(); i++)  {
            pageInfo=new PdfDocument.PageInfo.Builder(992, 1432, 1).create();
            page=document.startPage(pageInfo);
            canvas=page.getCanvas();
            image=BitmapFactory.decodeFile(list.get(i));
            image=Bitmap.createScaledBitmap(image, 980, 1420, true);
            image.setDensity(DisplayMetrics.DENSITY_300);
            canvas.setDensity(DisplayMetrics.DENSITY_300);
            canvas.drawBitmap(image, 0, 0, null);
            float rotation=0;
            try {
                ExifInterface exifInterface=new ExifInterface(selectedPhoto);
                int orientation=exifInterface.getAttributeInt(TAG_ORIENTATION, ORIENTATION_NORMAL);
                switch (orientation) {
                    case ExifInterface.ORIENTATION_ROTATE_90: {
                        rotation=-90f;
                        break;
                    }
                    case ExifInterface.ORIENTATION_ROTATE_180: {
                        rotation=-180f;
                        break;
                    }
                    case ExifInterface.ORIENTATION_ROTATE_270: {
                        rotation=90f;
                        break;
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            canvas.rotate(rotation);
            document.finishPage(page);
        }
        @SuppressWarnings("deprecation") String directory_path=Environment.getExternalStorageDirectory().getPath() + "/mypdf/";
        File file=new File(directory_path);
        if (!file.exists()) {
            //noinspection ResultOfMethodCallIgnored
            file.mkdirs();
        }
        @SuppressLint("SimpleDateFormat") String timeStamp=(new SimpleDateFormat("yyyyMMdd_HHmmss")).format(new Date());
        String targetPdf=directory_path + timeStamp + ".pdf";
         filePath=new File(targetPdf);
        try {
            document.writeTo(new FileOutputStream(filePath));
        } catch (IOException e) {
            Log.e("main", "error " + e.toString());
            Toasty.error(this, "Error making PDF" + e.toString(), Toast.LENGTH_LONG).show();
        }
        document.close();

任何建议或问题在哪里，没有错误代码或任何东西

Answer 1

绘制位图后不能旋转画布。你必须先旋转它，然后使用绘制位图即

        float rotation=0;
        try {
            ExifInterface exifInterface=new ExifInterface(selectedPhoto);
            int orientation=exifInterface.getAttributeInt(TAG_ORIENTATION, ORIENTATION_NORMAL);
            switch (orientation) {
                case ExifInterface.ORIENTATION_ROTATE_90: {
                    rotation=-90f;
                    break;
                }
                case ExifInterface.ORIENTATION_ROTATE_180: {
                    rotation=-180f;
                    break;
                }
                case ExifInterface.ORIENTATION_ROTATE_270: {
                    rotation=90f;
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        canvas.save();
        canvas.rotate(rotation);

        //canvas is rotated now use drawBitmap
        canvas.drawBitmap(image, 0, 0, null);
        canvas.restore();