액티비티간 데이터 주고 받기

MainActivity

메인 액티비티 에서 인텐트를 생성하고 인텐트에 putExtra 함수를 통해서 서브 액티비티로 전송한다.

startAcitivity(intent)를 실행하면 전달만 하고

startActivity(intent, num)을 실행하면 리턴을 받는다.

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(binding.root)

    with (binding) {
        button.setOnClickListener { view->
            var intent = Intent(this@MainActivity, SubActivity::class.java)
            intent.putExtra("from1", "hello bundle")
            intent.putExtra("from2", 2021)
            // startActivity(intent) 액티비티 전달 한다.
            startActivityForResult(intent, 99)
        }
    }
}

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

    if (resultCode == Activity.RESULT_OK) {
        when (requestCode) {
            99 -> {
                data?.getStringExtra("returnValue")
                    ?. let { message ->
                        Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
                    }
            }
        }
    }
}

main Activity XML

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    android:background="#FFFFFF"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/to1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="메인 액티비티"
        android:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="160dp"
        android:layout_marginTop="20dp"
        android:layout_marginEnd="160dp"
        android:text="서브 액티비티 실행"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/to1" />
</androidx.constraintlayout.widget.ConstraintLayout>

 

 

SubActivity

Main Acitivity에서 전달 받은 변수를 intent.getXXExtra 함수를 통하여 전달 받는다.

Main Activity로 리턴할때는

intent를 생성하고 intent에 put 함수를 통하여 작성하고 setResult를 호출한다.

class SubActivity : AppCompatActivity() {
    val binding by lazy { ActivitySubBinding.inflate(layoutInflater)}
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)

        with (binding) {
            to1.text = intent.getStringExtra("from1")
            to2.text = intent.getIntExtra("from2", 0).toString()

            btnClose.setOnClickListener {
                val returnIntent = Intent()
                val message = editMessage.text.toString()
                returnIntent.putExtra("returnValue", message)
                setResult(Activity.RESULT_OK, returnIntent)
                finish()
            }
        }
    }
}

 

sub Activity XML

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="107dp"
        android:layout_marginTop="284dp"
        android:layout_marginEnd="108dp"
        android:text="서브 액티비티"
        android:textSize="34sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/to2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:layout_marginEnd="108dp"
        android:text="to22"
        android:textSize="24sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <TextView
        android:id="@+id/to1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:text="to1"
        android:textSize="24sp"
        app:layout_constraintTop_toBottomOf="@+id/textView2"
        tools:layout_editor_absoluteX="107dp" />

    <EditText
        android:id="@+id/editMessage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="93dp"
        android:layout_marginEnd="108dp"
        android:ems="10"
        android:hint="전달할 메시지를 입력하세요"
        android:inputType="text"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        tools:layout_editor_absoluteY="413dp" />

    <Button
        android:id="@+id/btnClose"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="142dp"
        android:layout_marginTop="15dp"
        android:layout_marginEnd="178dp"
        android:text="액티비티 닫기"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/editMessage" />
</androidx.constraintlayout.widget.ConstraintLayout>