如何停止从Firebase检索数据？

Question

Stop retrieve data from Firebase after its loaded.

This is my code:

databaseReference.child("SHARE").addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot ds : dataSnapshot.getChildren()) {
            information spacecraft = ds.getValue(information.class);
            spacecrafts.add(spacecraft);
        }
        adapter adapterView= new adapter(MainActivity.this, spacecrafts);
        gridView.setAdapter(adapterView);
    }
}

Answer 1

Use addListenerForSingleValueEvent()

databaseReference.child("SHARE").addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            for (DataSnapshot ds : dataSnapshot.getChildren()) {

                information spacecraft = ds.getValue(information.class);
                spacecrafts.add(spacecraft);

            }
            adapter adapterView= new adapter(MainActivity.this, spacecrafts);
            gridView.setAdapter(adapterView);
        }

have a look on this answer https://stackoverflow.com/a/41579337/5868103

Answer 2

Use addListenerForSingleValueEvent instead of addValueEventListener if you want to read the whole data once.

Or if you want to get update from onDataChange, you can remove the listner,

 ValueEventListener eventListener = databaseReference.child("SHARE").addValueEventListener(new   ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot ds : dataSnapshot.getChildren()) {

            information spacecraft = ds.getValue(information.class);
            spacecrafts.add(spacecraft);

        }
        adapter adapterView= new adapter(MainActivity.this, spacecrafts);
        gridView.setAdapter(adapterView);
    }

To remove the listener,

databaseReference.child("SHARE").removeEventListener(eventListener);