How do you do mathematical action?

[courtlanda]

I've got two EditText, I've got to do the mathematical action of the 1EditText, 2EditText, and I can multiply 2

binding.inputQuantity
binding.inputPrice

Found an example.

int a = Integer.parseInt(binding.inputQuantity.getText().toString());
int b = Integer.parseInt(binding.inputPrice.getText().toString());
int res = (a * b) * 2;

binding.totalPrice.setText(String.valueOf(res));

But it works when EditText originally added some text. android:text="1" + Also, there is nothing to do with re-entry. I need it to be upgraded with an induction at EditText without any compression processors.

   <EditText

android:id="@+id/inputQuantity"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_weight="1"

android:layout_marginEnd="4dp"

android:background="@drawable/input_bg"

android:drawableStart="@drawable/ic_view"

android:drawablePadding="10dp"

android:ems="10"

android:fontFamily="@font/aldrich"

android:text="1"

android:hint="@string/_1"

android:inputType="number"

android:paddingStart="20dp"

android:paddingTop="13dp"

android:paddingEnd="20dp"

android:paddingBottom="13dp"

android:textColor="@color/colorWhite"

android:textColorHint="@color/colorWhite"

app:layout_constraintEnd_toEndOf="parent"

app:layout_constraintStart_toStartOf="parent"

app:layout_constraintTop_toBottomOf="@+id/inputTitle"

app:layout_editor_absoluteX="97dp"

app:layout_editor_absoluteY="248dp" />

&lt;EditText
    android:id="@+id/inputPrice"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:layout_marginStart="4dp"
    android:background="@drawable/input_bg"
    android:drawableStart="@drawable/ic_price"
    android:drawablePadding="10dp"
    android:ems="10"
    android:fontFamily="@font/aldrich"
    android:text="1"
    android:hint="@string/_2"
    android:inputType="number"
    android:paddingStart="20dp"
    android:paddingTop="13dp"
    android:paddingEnd="20dp"
    android:paddingBottom="13dp"
    android:textColor="@color/colorWhite"
    android:textColorHint="@color/colorWhite"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/inputTitle"
    app:layout_editor_absoluteX="97dp"
    app:layout_editor_absoluteY="248dp" /&gt;

Found what I need to do, but only when, from any field of EditText, the app closes because the field is empty, how can it be corrected?

    binding.inputPrice.addTextChangedListener(new TextWatcher() {

public void afterTextChanged(Editable s) {
    int a = Integer.parseInt(binding.inputQuantity.getText().toString());
    int b = Integer.parseInt(binding.inputPrice.getText().toString());

    int res = (a * b) * 2;
    binding.totalPrice.setText(String.valueOf(res));
}

public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

public void onTextChanged(CharSequence s, int start, int before, int count) {}

});
binding.inputQuantity.addTextChangedListener(new TextWatcher() {
public void afterTextChanged(Editable s) {
    int a = Integer.parseInt(binding.inputQuantity.getText().toString());
    int b = Integer.parseInt(binding.inputPrice.getText().toString());

    int res = (a * b) * 2;
    binding.totalPrice.setText(String.valueOf(res));
}

public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

public void onTextChanged(CharSequence s, int start, int before, int count) {}

});

[Raziyah00]

That's what helped me solve this problem, namely the elimination of tey end catch!

private void gettingTotalPrice() {
binding.inputPrice.addTextChangedListener(new TextWatcher() {

    public void afterTextChanged(Editable s) {
        try {
            int a = Integer.parseInt(binding.inputQuantity.getText().toString());
            int b = Integer.parseInt(binding.inputPrice.getText().toString());

            int res = (a * b) * 2;
            binding.totalPrice.setText(String.valueOf(res));
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }

    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }
});

binding.inputQuantity.addTextChangedListener(new TextWatcher() {

    public void afterTextChanged(Editable s) {
        try {
            int a = Integer.parseInt(binding.inputQuantity.getText().toString());
            int b = Integer.parseInt(binding.inputPrice.getText().toString());

            int res = (a * b) * 2;
            binding.totalPrice.setText(String.valueOf(res));
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }
    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }
});

}