android - 保存图片 EXTRA_OUPUT 为空 onActivityResult

Question

我在一个 Activity 中加载了 fragment 。

在此 fragment 中，我将事件 onClick 设置为按钮以拍照。我想将这张照片保存在内部存储中的特定文件夹中。

这是我的 fragment 类，我尝试了很多不同的解决方案，但我不明白为什么 mCurrentPhotoPath 被创建但没有被拍摄的照片填充(SkImageDecoder::Factory 返回 null)。

这是我的 fragment 类(我删除了部分代码)

public class Q3Fragment extends Fragment {

private OnFragmentInteractionListener mListener;
private Spinner field;
private int TAB_ID = 1;
private int Q_ID = 3;

private final static String DEBUG_TAG = "PHOTOMANAGER";
private String mCurrentPhotoPath;

private ImageView imagePreview;
private String filePath = "";
Intent takePictureIntent;
private PhotoManager pm;

public static Q3Fragment newInstance(String type) {
    Q3Fragment fragment = new Q3Fragment();
    Bundle args = new Bundle();
    args.putString("type", type);
    fragment.setArguments(args);
    return fragment;
}
public Q3Fragment() {}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    final View view = inflater.inflate(R.layout.fragment_q3, container, false);


    /////////////

    imagePreview = (ImageView) view.findViewById(R.id.q4imgPreview);



    takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    Button buttonPhoto = (Button) view.findViewById(R.id.q4BtnPhoto);
    buttonPhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            File photoFile = null;
            try {
                photoFile = createImageFile();
            } catch (IOException ex) {

            }
            // Continue only if the File was successfully created
            if (photoFile != null) {
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
                        Uri.fromFile(photoFile));
                startActivityForResult(takePictureIntent, 11);
            }


        }

    });

    /////////////

    return view;

}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mListener = (OnFragmentInteractionListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnFragmentInteractionListener");
    }
}

@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

public interface OnFragmentInteractionListener {
    // TODO: Update argument type and name
    public void onFragmentInteraction(Boolean valid,int qId);
}






@Override
public void onActivityResult(int requestCode, int resultCode,
                             Intent data) {
    Log.d("Fragment PHOTOMANAGER","onActivityResult");
    // lors du resultat de l'intent (lorsqu'on clique sur save la photo)

    try {
        handleSmallCameraPhoto();
    } catch (IOException e) {
        e.printStackTrace();
    }

    if(data != null) {
        getActivity().getContentResolver().delete(data.getData(), null, null);
    }


}


// on enregistre la photo
private void handleSmallCameraPhoto() throws IOException {


    File f = new File(mCurrentPhotoPath);
    Uri contentUri = Uri.fromFile(f);

    if(f.exists()){
        Log.d(DEBUG_TAG,"FILE EXISTS " + mCurrentPhotoPath);
    }

    // here the bitmap not containing picture.
    Bitmap mBitmap = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), contentUri);

    imagePreview.setImageBitmap(mBitmap);
    filePath = saveToInternalStorage(mBitmap);


}


// methode pour sauvegarder une photo (min ou full)
private String saveToInternalStorage(Bitmap bitmapImage){

    ContextWrapper cw = new ContextWrapper(getActivity().getApplicationContext());

    Log.d(DEBUG_TAG,"saveToInternalStorage");

    File directory = cw.getDir("imageDir_"+getArguments().getString("type"), Context.MODE_PRIVATE);

    String fileName;



    fileName = "q" + Q_ID + ".jpg";


    // Create imageDir
    File mypath = new File(directory, fileName);

    FileOutputStream fos = null;
    try {

        fos = new FileOutputStream(mypath);

        // Use the compress method on the BitMap object to write image to the OutputStream
        bitmapImage.compress(Bitmap.CompressFormat.JPEG, 80, fos);
        fos.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
    Log.d(DEBUG_TAG,"FILE SAVED "+mypath.getAbsolutePath());
    return mypath.getAbsolutePath();
}

private File createImageFile() throws IOException {
    // Create an image file name
    String imageFileName = "q" + Q_ID +"photo";
    ContextWrapper cw = new ContextWrapper(getActivity().getApplicationContext());

    Log.d(DEBUG_TAG,"saveToInternalStorage");

    File directory = cw.getDir("imageDir_"+getArguments().getString("type"), Context.MODE_PRIVATE);
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            directory      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();
    Log.d(DEBUG_TAG," createcontainer file "+mCurrentPhotoPath);
    return image;
}


}

在此先感谢您的帮助..

Answer 1

让我提一下 Android 中的一个关键概念，需要用它来理解为什么您的代码不能按原样运行。 ACTION_IMAGE_CAPTURE Intent 启动另一个应用。在这种情况下，相机应用程序可以完成工作。 EXTRA_OUTPUT 告诉调用的应用程序(即相机应用程序)将拍摄的照片保存在文件系统中的何处。

问题是应用可能只能访问它们自己的私有(private)内部存储空间。因此，相机应用程序无法将图片保存在调用者应用程序(即您的应用程序)的私有(private)存储空间中。

请注意，您正在调用 ContextWrapper.getDir，它指向您应用的私有(private) 存储中的一个目录。

如果您想将图片存储在您应用的私有(private)存储中，您必须暂时将图像存储在两个应用都可以访问的位置，然后 onActivityResult 将图片复制到您应用的私有(private)存储中。