All Questions
16
questions
0
votes
1
answer
377
views
How to fix 'java.lang.ClassCastException: Activity must implement fragment's callbacks'
I am a beginner who am writing a code that consists of two activities. Both have their own Fragments. On the first activity (in its fragment), the user input some fields. The result will be displayed ...
1
vote
1
answer
2k
views
returning an object from an android ViewModel to the fragment from a callback function
I am using ViewModel in android to obtain an object and then pass it to a fragment to update UI components. I am trying to obtain the value of the object asynchronously and then pass the object to the ...
- 133
11
votes
1
answer
1k
views
Fragment interaction callbacks: onAttach() vs setter
I'm trying to implement a nice, reusable Fragment and I'm having a hard time choosing a pattern of setting interaction callbacks. I am of course familiar with the docs, but I have some doubts ...
- 2,839
0
votes
1
answer
332
views
How to do custom async callbacks like Android Fragments do?
after having so much fun with Android fragments talking to each other and to the activity. I'm excited to try making some async callbacks from a background service. For my purpose, I just want a ...
- 1,381
0
votes
2
answers
750
views
Android - Can't access onSuccess of callback after login with Facebook in fragment
I have successfully logged in facebook. But, I can't access token or user profile from onSuccess method of callback. I have added callbackManager.onActivityResult in onActivityResult. I can login, but ...
- 557
11
votes
4
answers
4k
views
is it necessary to set Fragment interface listeners to null on detach?
In Fragment examples involving callbacks, usually they assign the listener in the onAttach method and then set the listener to null in the onDetach method.
Is this last part necessary? Doesn't the ...
0
votes
0
answers
40
views
How do I change ListView data that is stored in a Fragment (being loaded in mainactivity) through another activity
Okay, so my question might be a bit hard to understand so I'll try to explain it more clearly.
I have 3 files, 1 file is a fragment which has a ListView and that file extends ListFragment, another ...
- 573
1
vote
0
answers
281
views
Android Fragment/Activity Callbacks: Caller and Callee
Recently, while learning Android development, I learned that fragments can communicate with other fragments by defining a callback interface within the fragment and having the parent activity ...
- 11
3
votes
0
answers
109
views
Android "Sticky" interface callbacks
This question is more an architectural question more than an actual implementation.
In very basic terms I have network calls made to web services in and android app. When the network call is complete,...
- 1,349
0
votes
3
answers
875
views
How can class.this in a callback can be null?
I have a Fragment. In this Fragment I run a http request on an json-rpc. To handle the result I have something like this in my Callback.
FragmentClass.this.getActivity().runOnUiThread(new Runnable() {...
- 325
3
votes
2
answers
8k
views
Cyclic inheritance with Android development - fragments, activities and interfaces
I have an app with several fragments and one activity that manages them. In order to avoid coupling between fragments all interactions and changes go through the activity - but here's my problem - I ...
- 243
0
votes
2
answers
701
views
Callback throwing NullPointerException (Fragment out of Adapter)
I'm trying to get information out of my AlertDialog. After a click on a deletebutton in my recyclerView, the user is asked if he is sure. If "yes" the selected Dataset should be deleted. With this ...
- 347
0
votes
1
answer
453
views
Getting NullPointerException in OnResume() using Retrofit
We are trying to read a JSON file from a server and display it on our Android app using the Retrofit GET function.
We based our code on a existing and working Android app, but instead of an Activity, ...
- 3,508
1
vote
1
answer
944
views
OnActivityResult not call inside fragment but the Main Activity in android
I am working on a fragment that call camera.
startActivityForResult(intent, REQUEST_CAMERA);
The problem is , if I overwrite the onActivityResult inside the fragment, it does not call,
@Override
...
- 13.5k
-1
votes
2
answers
549
views
NullPointerException when change fragment and using callback
I have one problem with changing Fragments, I use spinner in action bar to do this, and sometimes button in alertdiaolog. And when I push the button I have NullPointerException.
This is my code of ...
- 584