我目前正在遵循这个指南https://developer.android.com/training/camera/photobasics#taskpath.
我正在尝试拍摄一张照片，并将其添加到我的图库中，但每当我拍摄一张照片时，任何内容都不会添加到图库或存储它的sd卡中。下面是我用java编写的使用相机拍照的代码。

private void dispatchTakePictureIntent() {
    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
        }
        // 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_IMAGE_CAPTURE);
        }
    }
}

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
    currentPhotoPath = image.getAbsolutePath();
    return image;
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(resultCode == Activity.RESULT_OK) {
        switch (requestCode) {
            case REQUEST_IMAGE_CAPTURE:
                galleryAddPic();
        }
    }
}

private void galleryAddPic() {
    Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
    File f = new File(currentPhotoPath);
    Uri contentUri = Uri.fromFile(f);
    mediaScanIntent.setData(contentUri);
    this.sendBroadcast(mediaScanIntent);
}

我认为在这里生成uri有问题，或者没有正确地放置额外的uri。有什么建议要解决吗？

if (photoFile != null) {
    Uri photoURI = FileProvider.getUriForFile(this,
        "com.example.android.fileprovider",
        photoFile);
    takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
    startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}