Android Firebase - 根据微调器更改来自 firebase 的列表视图数据

Question

Hi I'm trying to display certain data on my listview based on item selected from a spinner. This is how the display page currently looks. It's reading all the data from the node. Because "Running" is selected on the spinner above, I want the list view to only show Running.

Here is the code i'm using to read all the data.

 @Override protected void onStart() { super.onStart(); //reading data to listview, every time its saved currentUserDB2.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { cardiosList.clear(); for(DataSnapshot cardioHistorySnapshot: dataSnapshot.getChildren()){ Cardio cardio = cardioHistorySnapshot.getValue(Cardio.class); cardiosList.add(cardio); } CardioHistoryList adapter = new CardioHistoryList(Cardio_History.this, cardiosList); ListViewCardioHistory.setAdapter(adapter); } @Override public void onCancelled(DatabaseError databaseError) { } }); }

Working code

 spinnerCardioHistory.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) { String name = spinnerCardioHistory.getSelectedItem().toString(); currentUserDB2.orderByChild("detailCategory").equalTo(name).addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { cardiosList.clear(); for (DataSnapshot cardioHistorySnapshot: dataSnapshot.getChildren()){ Cardio cardio = cardioHistorySnapshot.getValue(Cardio.class); cardiosList.add(cardio); } CardioHistoryList adapter = new CardioHistoryList(Cardio_History.this, cardiosList); ListViewCardioHistory.setAdapter(adapter); } @Override public void onCancelled(DatabaseError databaseError) { } }); } @Override public void onNothingSelected(AdapterView<?> adapterView) { } });

Answer 1

If you want only the word Running to be displayed then do the following:

 String text = spinner.getSelectedItem().toString();
 FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
 DatabaseReference currentUserDB2=FirebaseDatabase.getInstance().getReference().child("Cardio").child(user.getUid());
 currentUserDB2.orderByChild("detailCategory").equalTo(text).addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            cardiosList.clear();
            for(DataSnapshot cardioHistorySnapshot : dataSnapshot.getChildren()){

               String category=cardioHistorySnapshot.child("detailCategory").getValue().toString();
                cardiosList.add(category);
            }

            CardioHistoryList adapter = new CardioHistoryList(Cardio_History.this, cardiosList);
            ListViewCardioHistory.setAdapter(adapter);

First you get the select texted that is in the spinner String text = spinner.getSelectedItem().toString();

then you add it in the query orderByChild("detailCategory").equalTo(text) and then retrieve from the database and it will only add the word that is selected in the spinner which is "Running".