OnActivityResult 有时不会在 ACTION_GET_CONTENT 意图后调用

Question

I'm working on an image editing Android application. In one of my activities I call an intent to pick an image from the gallery in onCreate() like this:

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);

Then I receive data like this:

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

    if (requestCode == PICK_IMAGE && resultCode == Activity.RESULT_OK && data != null) {
        Crashlytics.log("Data received from image pick intent");
        imageUri = data.getData();
        loadImage();
    } else {
        //if we do not select a picture, go back to the dashboard
        Crashlytics.log("Data not received");
        onBackPressed();
        Log.d(TAG, "no picture selected");
    }
}

The loadImage method:

private void loadImage() {
    try {
        photoBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
    } catch (IOException e) {
        Crashlytics.log("IOException from getBitmap");
        Log.d(TAG, e.getMessage());
        showToastAndPressBack();
        return;
    }

    if (photoBitmap == null) {
        Crashlytics.log("photoBitmap is null in onActivityResult");
        showToastAndPressBack();
        return;
    }

    Display display = getWindowManager().getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    imgVWidth = size.x;
    int height = size.y;
    imgVHeight = (int) (((float) imgVWidth / photoBitmap.getWidth()) * photoBitmap.getHeight());
    photoInImgViewBitmap = Bitmap.createScaledBitmap(photoBitmap, imgVWidth, imgVHeight, true);
    imageAlreadyPicked = true;
}

Now my problem is that sometimes I see NPE-s in Crashlytics claiming that photoBitmap is null when the user presses the next button.

@OnClick(R.id.toolbar_next)
void onToolbarNextClick() {
    float originalScale = (float) (previewImageView.getHeight()) / (float) (photoBitmap.getHeight());
    ...
}

The only Crashlytics log I see is that the user leaves for the intent (I placed a Crashlytics log inside onPause ). No log for onActivityResult , so my best guess is that onActivityResult is not called, thus my bitmap is not loaded, thus it will be null when the user presses next.

Question: why is onActivityResult called sometimes, and sometimes not? Are there any other possible causes of photoBitmap being null?

Answer 1

You must add following code for taking images from devices

choosebtn.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View v) {
         Intent i1=new Intent();
         i1.setType("image/*");
         i1.setAction(Intent.ACTION_GET_CONTENT);
         startActivityForResult(i1,1);
      }
});


@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == 1 && resultCode == RESULT_OK && data != null && data.getData() != null)
    {
        imguri=data.getData();
        mainpreview.setImageURI(data.getData());
    } else {
        Toast.makeText(getApplicationContext(),"please choose image",Toast.LENGTH_SHORT).show();
    }
}

Answer 2

To start camera activity use this code

Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);

To get bitmap

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

  if(resultCode == Activity.RESULT_OK){
    if(requestCode==CAMERA_REQUEST) {
      Bitmap photo = (Bitmap) data.getExtras().get("data"); }
    }else{
      //Camera request cancelled
  }
}

Answer 3

Try this it worked perfect

     Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(i, LOAD_IMAGE_RESULTS);

  @SuppressLint("Recycle")
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

           if (requestCode == LOAD_IMAGE_RESULTS && resultCode == RESULT_OK && data != null) {
                    // Let's read picked image data - its URI
                    Uri pickedImage = data.getData();

                    // Let's read picked image path using content resolver
                    String[] filePath = {MediaStore.Images.Media.DATA};
                    @SuppressLint("Recycle") Cursor cursor = null;
                    if (pickedImage != null) {
                        cursor = getContentResolver().query(pickedImage, filePath, null, null, null);
                    }
                    if (cursor != null) {
                        cursor.moveToFirst();

                        String imagePath = cursor.getString(cursor.getColumnIndex(filePath[0]));
      }
    }
}

now you can convert imagepath to bitmap

Answer 4

Call super.onActivityResult after your code last line of method. You've told android your done when you call the super.

Also I noticed your logging a char sequence. Don't do that Your not going to fix anything with this.

 Crashlytics.log("Data not received");

You need to save some data. Considered the user canceled because your code doesn't capture this.

/* assume log method has an int input */

Crashlytics.log("Data not received");
Crashlytics.log(requestCode);
Crashlytics.log(resultCode);

Answer 5

Use this to select from gallery:

Intent i = new Intent(Intent.ACTION_PICK);
i.setType("image/*");
startActivityForResult(i, REQUEST_CODE);

Now u will get a callback in onActivityResult:

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case REQUEST_CODE:
            if (resultCode != RESULT_CANCELED) {
//use data to get the selected image
            }
            break;
    }
}