Android

override fun onOptionsItemSelected(item: MenuItem): Boolean {
       
        return when (item.itemId) {
            R.id.action_locate -> true
            else -> super.onOptionsItemSelected(item)
        }
        return when (item.itemId) {
            R.id.action_scanner -> true
            else -> super.onOptionsItemSelected(item)
        }
        return when (item.itemId) {
            R.id.action_qrcodescanner -> true
            else -> super.onOptionsItemSelected(item)
        }
        return when (item.itemId) {
            R.id.action_mainsite -> true
            else -> super.onOptionsItemSelected(item)
        }

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.sdf.sdf.MainActivity">

<item
    android:id="@+id/action_locate"
    android:orderInCategory="100"
    android:title="Locate Vehicle"
    app:showAsAction="never" />
<item
    android:id="@+id/action_scanner"
    android:title="BarCode Scanner"
    android:orderInCategory="100"
    app:showAsAction="never" />
<item
    android:id="@+id/action_qrcodescanner"
    android:icon="@drawable/ic_scanner_black_24dp"
    android:orderInCategory="100"
    android:title="Q.R. Code Scanner"
    app:showAsAction="never" />
<item
    android:id="@+id/action_mainsite"
    android:icon="@android:drawable/checkbox_on_background"
    android:orderInCategory="100"
    android:title="TheSite.com"
    app:showAsAction="never" />
    
</menu>

public static DateTime Convert_To_System_DateTime(string input)
   {
      return DateTime.ParseExact(input, "yy/MM/dd HH:mm:ss", CultureInfo.InvariantCulture);
   }

I'm looking for a way to implement a simple list view scrolling in my Firebase app, but I am not getting any way out how to implement this. I have already tried 2-3 tutorials and documentation available on the Internet, but didn't the required result.

In my app I want scrolling like at starting first 10 list items load then each time on scrolling next 10 or 20 items will load until the last item appears at the bottom of the list.

So I tried retrieving first 10 items the following way :



<pre>private void readsposts(){

        DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
        reference.keepSynced(true);

        reference.child("Posts")
                .limitToLast(10)
                .addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                       
                        postList.clear();
                        for(DataSnapshot snapshot:dataSnapshot.getChildren()){
                            Post post = snapshot.getValue(Post.class);
                            for(String id:followingList){

                                if(post.getPublisher()!=null && post.getPublisher().equals(id)){

                                    postList.add(post);
                                   

                                }

                            }

                            if(post.getPublisher()!=null && post.getPublisher().equals(firebaseUser.getUid())){
                                postList.add(post);

                            }

                            postAdapter.notifyDataSetChanged();


                        }
                        
                        mProgressBar.setVisibility(RecyclerView.GONE);

                    }


                    @Override public void onCancelled(DatabaseError databaseError) {
                        mProgressBar.setVisibility(RecyclerView.GONE);
                    }
                });
    }

AndroidEnvironment.UnhandledExceptionRaiser += (sender, e) => ...
TaskScheduler.UnobservedTaskException += (sender, e) => ...
AppDomain.CurrentDomain.UnhandledException += (sender, e) => ...

throw 0xBEEF;