Android BitmapFactory.decodeFile gibt Null zurück

Question

Ich rufe Activity.requestPermissions (READ_EXTERNAL_STORAGE) auf und nachdem Benutzer auf ALLOW klicken, versuche ich BitmapFactory.decodeFile (Pfad) zu verwenden, aber es gibt null zurück. Und wenn die Erlaubnis bereits erteilt ist alles in Ordnung. Was ist los mit dir?

ImageChooser Klasse

public class ImageChooser { 

    private final static int GET_IMAGE_REQUEST = 1; 

    private final static int PERMISSIONS_REQUEST = 2; 

    public interface Callback { 
     void onImageChosen(Bitmap image); 
    } 

    private Activity activity; 
    private Fragment fragment; 
    private Callback callback; 

    private String capturedImagePath; 

    public ImageChooser(Activity activity, Fragment fragment, Callback callback) { 
     this.activity = activity; 
     this.fragment = fragment; 
     this.callback = callback; 
    } 

    public void choose() { 
     boolean readStorageGranted = PermissionsManager 
       .isPermissionGrantedReal(activity, Permission.READ_EXTERNAL_STORAGE); 
     boolean cameraGranted = PermissionsManager 
       .isPermissionGrantedReal(activity, Permission.CAMERA); 

     if (readStorageGranted && cameraGranted) { 
      chooseImage(); 
     } else { 
      fragment.requestPermissions(new String[] { 
        Permission.CAMERA.permission, 
        Permission.READ_EXTERNAL_STORAGE.permission 
      }, PERMISSIONS_REQUEST); 
     } 
    } 

    private void chooseImage() { 
     Intent pickIntent = new Intent(Intent.ACTION_PICK); 
     pickIntent.setType("image/*"); 

     String filename = "image.png"; 
     String dir = activity.getExternalCacheDir().getAbsolutePath(); 

     capturedImagePath = dir + "/" + filename; 
     File file = new File(capturedImagePath); 

     Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); 
     captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file)); 

     Intent chooserIntent = Intent.createChooser(pickIntent, 
       activity.getString(R.string.take_choose_photo)); 

     chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[] { captureIntent }); 

     fragment.startActivityForResult(chooserIntent, GET_IMAGE_REQUEST); 
    } 

    public void handleOnActivityResult(int requestCode, int resultCode, Intent data) { 
     if (requestCode == GET_IMAGE_REQUEST && resultCode == Activity.RESULT_OK) { 
      Bitmap image = null; 

      String picturePath = null; 

      if (data == null) { // From Camera. 
       File imageFile = new File(capturedImagePath); 
       if (imageFile.exists()) { 
        image = BitmapFactory.decodeFile(imageFile.getAbsolutePath()); 
       } 
      } else { // From Gallery. 
       Uri selectedImage = data.getData(); 

       String[] filePathColumn = { MediaStore.Images.Media.DATA }; 

       Cursor cursor = activity.getContentResolver().query(selectedImage, filePathColumn, 
         null, null, null); 

       if (cursor != null) { 
        cursor.moveToFirst(); 

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]); 
        picturePath = cursor.getString(columnIndex); 
        cursor.close(); 

        image = BitmapFactory.decodeFile(picturePath); 
       } 
      } 

      if (image != null) { 
       callback.onImageChosen(image); 

      } 
     } 
    } 

    public void handleOnRequestPermissionsResult(int requestCode, String[] permissions, 
               int[] grantResults) { 
     if (grantResults.length > 0 && 
       grantResults[0] == PackageManager.PERMISSION_GRANTED && 
       grantResults[1] == PackageManager.PERMISSION_GRANTED) { 

      chooseImage(); 
     } 
    } 
} 

Beispiel des Verwendens

public class CustomizeFragment extends Fragment { 

    @Bind(R.id.add_image) 
    View addImageView; 

    @Bind(R.id.switch_button_off) 
    Button switchOffButton; 

    @Bind(R.id.switch_button_on) 
    Button switchOnButton; 

    @Bind(R.id.mb_image) 
    RoundedImageView imageView; 

    private ImageChooser imageChooser; 

    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     View v = inflater.inflate(R.layout.fragment_customize, container, false); 

     ButterKnife.bind(this, v); 

     return v; 
    } 

    @Override 
    public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
     super.onActivityCreated(savedInstanceState); 

     imageChooser = new ImageChooser(getActivity(), this, image -> { 
      addImageView.setVisibility(View.GONE); 
      imageView.setVisibility(View.VISIBLE); 

      imageView.setImageBitmap(image); 
     }); 
    } 

    @Override 
    public void onDestroyView() { 
     super.onDestroyView(); 

     ButterKnife.unbind(this); 
    } 

    @OnClick({R.id.add_image, R.id.mb_image}) 
    void onAddImageClick() { 
     imageChooser.choose(); 
    } 


    @Override 
    public void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 

     imageChooser.handleOnActivityResult(requestCode, resultCode, data); 
    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { 
     super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

     imageChooser.handleOnRequestPermissionsResult(requestCode, permissions, grantResults); 
    } 
} 

Answer 1

Vorwiegend BitmapFactory.decodeFile() null zurückgibt, ist das JPG-Bild, wie Auflösung hat, die eine Bitmap macht es braucht mehr Speicher als das Betriebssystem liefern kann. Versuchen Sie, es zu verkleinern.