Android Google Firebase数据库在Spinner上的查询

// 建立与Firebase数据库的连接
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference ref = database.getReference("your_database_reference");

// 查询数据
Query query = ref.orderByChild("category").equalTo("your_category");
query.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        List<String> options = new ArrayList<>();
        for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
            String option = snapshot.child("option").getValue(String.class);
            options.add(option);
        }
        
        // 将查询结果展示在Spinner上
        ArrayAdapter<String> adapter = new ArrayAdapter<>(context, android.R.layout.simple_spinner_item, options);
        spinner.setAdapter(adapter);
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        // 处理查询取消或失败的情况
    }
});