如何将 integer 变量从活动传递到片段？

Question

I have an activity with two variables

int cifracero and int cifrauno

I want to pass those variables to a fragment to be shown in some TextViews as the result of the multiplication made in the previous screen...like a "Congratulations, the multiplication was..."

I need to do something like a bundle to pass the variables as arguments of the second screen, in this case a fragment.

And then I have a third variable resultado which is the result of the multiplication of cifracero and cifrauno

This is the activity code

    package com.example.aprendelastablasdemultiplicar;

    import androidx.activity.ComponentActivity;
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.fragment.app.Fragment;
    import androidx.fragment.app.FragmentManager;
    import androidx.fragment.app.ListFragment;

    import android.content.Intent;
    import android.net.Uri;
    import android.os.Bundle;
    import android.text.Editable;
    import android.text.TextWatcher;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;

    import org.w3c.dom.Text;

    public class quizingresar extends ComponentActivity {

        private EditText cifracero;
        private EditText cifrauno;
        private TextView resultado;
        private Button calcular;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_quizingresar);


  
            cifracero = (EditText) findViewById(R.id.cifracero);
            cifrauno = (EditText) findViewById(R.id.cifrauno);
            resultado = (TextView) findViewById(R.id.resultado);
            calcular = (Button)findViewById(R.id.calcular);

             TextWatcher textWatcher = new TextWatcher() {
                 @Override
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

                 @Override
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                    int multiplicationResult = multiplicarValores();
                resultado.setText(Integer.toString(multiplicationResult));
                 }

                @Override
                public void afterTextChanged(Editable s) {

        }


    };

            cifracero.addTextChangedListener(textWatcher);
            cifrauno.addTextChangedListener(textWatcher);

        calcular.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openCongratulationsCalcular();

    }
});
}


        private int multiplicarValores() {
            final String strnumber0 = cifracero.getText().toString();
            final String strnumber1 = cifrauno.getText().toString();
            int number0 = 0;
            int number1 = 0;

            try {
                number0 = Integer.parseInt(strnumber0);
    } catch (NumberFormatException e) {

    }
            try {
                number1 = Integer.parseInt(strnumber1);
    } catch (NumberFormatException e) {

    }

             return number0 * number1;
}

    public void openCongratulationsCalcular(){
        Intent intent = new Intent(this, congratulationscalcular.class);
        startActivity(intent);

}

}

I need to recover the variables from the previous screen to be shown in the new fragment screen

Answer 1

You can have both of your fragments share the data between them by having them both under the same viewmodel, as shown here .

If you are going to be swapping screens, I think a very efficient solution would be to pass the desired data from one (screen) fragment to another using attributes in your Navigation Graph. Shown here .

Take a look at Data-Binding as well if you'd like, might be useful.

Answer 2

Intent intent = new Intent(this, DisplayMessageActivity.class);
        String result = resultado.getText().toString();
        intent.putExtra("EXTRA_MESSAGE", result);
        startActivity(intent);

to get the message that was passed by the first activity

Intent intent = getIntent();
String message = intent.getStringExtra("EXTRA_MESSAGE");