Dynamic total according to Android Numberpicker

Question

I am using Numberpicker so that the user selects the quantity. Each numberpicker has a total that already appears on the screen according to the amount selected by the user.

Example: Numberpicker 1 = qnt 3 = R$ 15,00

Numberpicker 2 = qnt 2 = R$10,00

Numberpicker 3 = qnt 4 = R$8,00

The total of each item is dynamic, so change the quantity already shows the total value in front.

I am stuck in the overall total. That overall total would take all the totals and sum and return a dynamic overall total.

Below the listeners of Numberpickers

np_Garrafa.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {

            qntGarrafa = numEscolhido;
            total_Garrafa = qntGarrafa * 10;
            txt_totalGarrafa.setText("R$ " + total_Garrafa);
            Log.i("garrafa", String.valueOf(qntGarrafa));
        }
    });

    np_Garrafao10.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {

            qntGarrafao10 = numEscolhido;
            total_Garrafao10 = qntGarrafao10 * 5;
            txt_totalGarrafao10.setText("R$ " + total_Garrafao10);
            Log.i("garrafa10", String.valueOf(qntGarrafao10));

        }
    });

    np_Garrafao20.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {

            qntGarrafao20 = numEscolhido;
            total_Garrafao20 = qntGarrafao20 * 10;
            txt_totalGarrafao20.setText("R$ " + total_Garrafao20);
            Log.i("garrafa20", String.valueOf(qntGarrafao20));

        }
    });

I tried to put in each listener a variable that would receive the total of each item and display in the overall textview. But if user decrease the amount it still continues adding.

Answer 1

You could try something like this:

float totalGeral = 0.0f;
// cria uma variável total geral
np_Garrafa.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
    @Override
    public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {
        qntGarrafa = numEscolhido;
        total_Garrafa = qntGarrafa * 10;
        totalGeral+=total_Garrafa;
        // soma o q tem na garrafa ao total geral
        txt_totalGarrafa.setText("R$ " + total_Garrafa);
        Log.i("garrafa", String.valueOf(qntGarrafa));
    }
});

np_Garrafao10.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
    @Override
    public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {
        qntGarrafao10 = numEscolhido;
        total_Garrafao10 = qntGarrafao10 * 5;
        totalGeral+=total_Garrafa10;
        // soma o q jah tem no totalGeral + garrafa10
        txt_totalGarrafao10.setText("R$ " + total_Garrafao10);
        Log.i("garrafa10", String.valueOf(qntGarrafao10));

    }
});

np_Garrafao20.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
    @Override
    public void onValueChange(NumberPicker numberPicker, int i, int numEscolhido) {

        qntGarrafao20 = numEscolhido;
        total_Garrafao20 = qntGarrafao20 * 10;
        totalGeral+=total_Garrafa20;
        // soma o q jah tem no toalGeral + o que tem na garrafa20
        txt_totalGarrafao20.setText("R$ " + total_Garrafao20);
        Log.i("garrafa20", String.valueOf(qntGarrafao20));

    }
});
// dai
txt_totalGeral.SetText("R$ " + totalGeral);

hope it works.

Let me know if it works