Fragment中的OnActivityResult不被调用

Question

I know this question have been asked a few times before. I've tried all of them but it doesn't work in my case.

I'm trying to upload an image from Gallery or capture from Camera via intents. So, the implementation is to call onActivityResult from the Fragment. When the button in Fragment is clicked, it returns NullPointerException in MainActivity.

Here's the logcat error:

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=65538, result=0, data="imagepath"} to activity {com.example/com.example.activity.MainActivity}: java.lang.NullPointerException

In MainActivity :

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

    // Null Pointer Exception here
    Session.getActiveSession().onActivityResult(this, requestCode,
            resultCode, data);
}

Session.getActiveSession() came from Facebook as I am using Facebook SDK login.

If I comment out this line, the Camera/Gallery intent worked BUT I can't use Facebook SDK login button.

In UploadFragment :

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

    if (resultCode != getActivity().RESULT_OK)
        return;

    switch (requestCode) {
        case CAMERA_REQUEST:
        //
        case SELECT_PICTURE:
        //
    }
}

The fragment's ActivitResult is called via this:

    btnCamera.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            try {
                startActivityForResult(cameraIntent, CAMERA_REQUEST);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });

    btnGallery.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // To open up a gallery browser
            startActivityForResult(Intent.createChooser(intent, "Select Picture"), SELECT_PICTURE);
        }
    });

How do I solve this?

---

UPDATE

I noticed that if I have logged in to Facebook, the problem doesn't occur as it found an active session. Otherwise, an error will occur.

I'm guessing that Facebook Session throws the error since there is no session involved.

Refer to my solution below.

Answer 1

I noticed that I didn't logged in to Facebook. The problem here is that Facebook is trying to get its active session, but couldn't find it in the SharedPreference (I'm using both normal and social login).

Managed to solve the problem by a simple workaround.

Wrap the Session.getActiveSession with try-catch block. That will get rid of the crash.

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

    super.onActivityResult(requestCode, resultCode, data);

    try {
        Session.getActiveSession().onActivityResult(this, requestCode,
                resultCode, data);
    } catch (Exception e) {
        // do nothing
    }
}