从firebase检索所有值并将其放入TextView

Question

My Database Image from Firebase

我想检索Dosa和Dosa2并将其放入TextView。 下面是我尝试的代码，但我只能检索Dosa2。

mMessagesDatabaseReference = mFirebaseDatabase.getReference("messages");

// Attach a listener to read the data at our posts reference
        mMessagesDatabaseReference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                for (DataSnapshot postSnapshot: dataSnapshot.getChildren()) {
                    Food food = postSnapshot.getValue(Food.class);
                    foodnameTextView.setText(food.getFoodname()+"\n");
                }}

            @Override
            public void onCancelled(DatabaseError databaseError) {
                System.out.println("The read failed: " + databaseError.getCode());
            }
        });

Answer 1

因为你每次都在循环中设置textview。这样做： 在顶部初始化变量并将文本追加到循环中，而不是将其设置为textview

 mMessagesDatabaseReference = mFirebaseDatabase.getReference("messages");

    // Attach a listener to read the data at our posts reference
            String foodName="";
            mMessagesDatabaseReference.addValueEventListener(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    for (DataSnapshot postSnapshot: dataSnapshot.getChildren()) {
                        Food food = postSnapshot.getValue(Food.class);
                        foodName+=food.getFoodname()+"\n";

                    }
                    foodnameTextView.setText(foodName);
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {
                    System.out.println("The read failed: " + databaseError.getCode());
                }
            });