小编Gré*_*ado的帖子

当我在Firebase中寻找列表时,我想在屏幕上显示一个进度条.我怎样才能做到这一点？

现在的代码不显示进度条.如果你能帮助我,谢谢你.

@Override
protected void onResume() {
    super.onResume();
    openProgressBar();
    callConnection();
    mDatabaseReference.child("bakeries").addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if (dataSnapshot.getChildrenCount() > 0) {
                closeProgressBar();
                adapter = new FirebaseRecyclerAdapter<Bakery, BakeryViewHolder>(
                        Bakery.class,
                        R.layout.card_bakery,
                        BakeryViewHolder.class,
                        //referencing the node where we want the database to store the data from our Object
                        mDatabaseReference.child("bakeries").getRef()
                ) {
                    @Override
                    protected void populateViewHolder(BakeryViewHolder viewHolder, final Bakery model, final int position) {
                        if (tvNoBakeries.getVisibility() == View.VISIBLE) {
                            tvNoBakeries.setVisibility(View.GONE);
                        }
                        if (icBakery.getVisibility() == View.VISIBLE) {
                            icBakery.setVisibility(View.GONE);
                        }
                        viewHolder.tvBakeryName.setText(model.getFantasyName());
                        viewHolder.tvPhone.setText(model.getFone());
                        viewHolder.tvDistrict.setText(model.getAdress().getDistrict()); …