How to pass values from fragments in one activity to another activity?

Question

I am making a little quiz in an app that has two activities. one activity has fragments of the questions, and each question is answered with an editText. The fragments are contained inside a FrameLayout inside that activity, and when I reach the last question I have a "Finish" button.

What I want is that when someone finishes the quiz and clicks on the "Finish" button that is in the last fragment, it will move him to the second activity and check the results of the questions.

In other words, how can I get the values that were typed inside the editTexts in the previous activity from each fragment in order to check the answers in the second activity and show the results?

The quiz activity (main activity)

package com.example.ishihara_test

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.Button

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.main_activity)

        val plate1 = Frag_Plate1()
        val plate2 = Frag_Plate2()
        val plate3 = Frag_Plate3()

        val btnPrev = findViewById<Button>(R.id.btnPrev)
        val btnNext = findViewById<Button>(R.id.btnNext)


        supportFragmentManager.beginTransaction().apply {
            replace(R.id.flfragment, plate1)
            commit()
        }

        btnPrev.setOnClickListener {
            supportFragmentManager.beginTransaction().apply {
                if (plate2.isVisible) {
                    replace(R.id.flfragment, plate1)
                }
                if (plate3.isVisible) {
                    replace(R.id.flfragment, plate2)
                    btnNext.text = "Next"
                }
                commit()
            }
        }

        btnNext.setOnClickListener {
            supportFragmentManager.beginTransaction().apply {
                if (plate1.isVisible) {
                    replace(R.id.flfragment, plate2)
                }
                if (plate2.isVisible) {
                    replace(R.id.flfragment, plate3)
                    btnNext.text = "Finish"
                }
                commit()
            }
        }

    }
}

xml layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btnPrev"
        android:layout_width="129dp"
        android:layout_height="45dp"
        android:text="Previous" />

    <Button
        android:id="@+id/btnNext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Next" />

    <FrameLayout
        android:id="@+id/flfragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

all the fragments have this code:

package com.example.ishihara_test

import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.EditText

/**
 * A simple [Fragment] subclass.
 * Use the [Frag_Plate2.newInstance] factory method to
 * create an instance of this fragment.
 */
class Frag_Plate2 : Fragment(R.layout.frag_plate2) {
    
}

xml for fragments:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Frag_Plate2">

    <!-- TODO: Update blank fragment layout -->

    <TextView
        android:id="@+id/plate2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="What is the number on the plate?"
        android:textSize="20sp" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="395dp"
        android:layout_height="wrap_content"
        android:src="@drawable/plate2" />

    <EditText
        android:id="@+id/editTextTextAnswer"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:maxLines="1"
        android:inputType="number"
        android:hint="Write number here..." />

</RelativeLayout>

I prefer in kotlin, but java code also works in order to understand.
Note: I didn't put code snippets cause it's clearer what I said above, but if it helps I'll put.

Any help is greatly appreciated, thanks a lot :)

Can you share your code for your Parent Activity and the Fragment class? — Piyush Satija, May 11 '21 at 17:21
@PiyushSatija these are the codes of main activity and an example fragment inside its FrameLayout, I still have the result activity empty. — conan tannous, May 11 '21 at 17:37

score 0 · Answer 1 · answered May 11 '21 at 18:18

To Save an answer on one fragment and then so on repeat this step in every fragment the best way is to create an ArrayList(of Answers), before every fragment transaction add answer to this arraylist and send this arraylist to next fragment and repeat this until last fragment, On Last fragment Put your answer in this arraylist and then further Pass it to Your second activity.

On Second Activity Try a loop on Arraylist and get all your answers in relevant variables.

Second Solution is to Make a Abstract Class i.e. Friend.java / Friend.kt Extend it into your Base Activity, Create a function that receive answer from fragment and add it to arraylist(Created in Friend Class),

Friend.AnswerList(answer)

You can get this arraylist from Friend Class in your Second Activity.

How to pass values from fragments in one activity to another activity?

1 Answers1