Android Studio-如何从外部私人存储读取图像？

Question

我是Android编程的新手，我需要编写一个应用程序，拍摄一张照片然后对其进行处理。 https://developer.android.com/training/camera/photobasics-我复制了本教程中的步骤，并使用标准的相机应用程序拍照。当我运行相机应用程序时，我将来自外部私人存储的文件传递给相机，相机应将图片写入该文件。一切正常，我可以拍照，应用程序返回我的应用程序中的活动，但是现在我不知道如何获取这张照片。我有一个应该存储图像的文件的绝对路径，但是本教程并未涵盖我应该读取此文件的方式。教程提到了一个名为 openFileInput（）的函数，我尝试使用该函数，但是当我向其传递绝对路径时，我得到了一个异常，该异常告诉我传递给它的String对象中存在路径中断符。 / p>

String mCurrentPhotoPath;
/*Function creates a file in external private storage and stores path to it 
in mCurrentPhotoPath*/

private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();
    return image;
}

/*reakcjaZdjecie is called when user clicks button "Take a picture!"*/

public void reakcjaZdjecie(View widok) {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            // Error occurred while creating the File
            Log.i("Pictures", "Couldn't create file");
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                    "com.example.android.fileprovider",
                    photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        switch(requestCode)
        {
            case REQUEST_TAKE_PHOTO:
                Log.d("Pobrano zdjecie", mCurrentPhotoPath);
                try{
                    openFileInput(mCurrentPhotoPath);
                }catch(FileNotFoundException e)
                {
                    Log.d("Result", "Couldn't find file");
                    e.getStackTrace();
                }
                break;
        }
    }
}