Activity から結果を取得する

class MainActivity : AppCompatActivity() {

companion object {

const val REQUEST_CODE = 100

}

private lateinit var binding: ActivityMainBinding

private val nextButtonListener = View.OnClickListener {

val intent = Intent(this, SubActivity::class.java)

startActivityForResult(intent, REQUEST_CODE)

}

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

binding = ActivityMainBinding.inflate(layoutInflater)

setContentView(binding.root)

binding.nextButton.setOnClickListener(nextButtonListener)

}

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {

super.onActivityResult(requestCode, resultCode, data)

if (requestCode == REQUEST_CODE) {

if (resultCode == RESULT_OK && data != null) {

val person = data.getSerializableExtra(SubActivity.PERSON_EXTRA) ?: return

if (person is Person) {

binding.nameTextView.text = person.name

binding.ageTextView.text = person.age.toString()

binding.isMarriedTextView.text = if (person.isMarried) "married" else "un married"

}

}

}

}

}

class SubActivity : AppCompatActivity() {

companion object {

const val PERSON_EXTRA = "person"

}

private lateinit var binding: ActivitySubBinding

private val backButtonListener = View.OnClickListener {

val person = Person("John Doe", 999, false)

val intent = Intent().apply {

putExtra(PERSON_EXTRA, person)

}

setResult(RESULT_OK, intent)

finish()

}

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

binding = ActivitySubBinding.inflate(layoutInflater)

setContentView(binding.root)

setResult(RESULT_CANCELED)

binding.backButton.setOnClickListener(backButtonListener)

}

}

data class Person(

val name: String,

val age: Int,

val isMarried: Boolean = false

) : Serializable {

override fun toString(): String =

"name: $name, age: $age, ${if (isMarried) "Married" else "Un married"}"

}