라디오 버튼

 

라디오 버튼 클릭시 선택된 항목을
텍스트박스에 출력해보자

 

1. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">
    <RadioGroup
            android:id="@+id/radioGroup"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintBottom_toBottomOf="parent">
        <RadioButton
                android:text="사과"
                android:checked="true"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/radio1"/>
        <RadioButton
                android:text="바나나"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/radio2"/>
        <RadioButton
                android:text="오렌지"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/radio3"/>
    </RadioGroup>
    <TextView
            android:id="@+id/textView"
            android:text="TextView"
            android:layout_width="203dp"
            android:layout_height="48dp"
            app:layout_constraintTop_toBottomOf="@+id/radioGroup"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            android:layout_marginTop="28dp"
            app:layout_constraintHorizontal_bias="0.501"/>
</androidx.constraintlayout.widget.ConstraintLayout>

2. build.gradle - android{···}내에 kotlinOptions 밑에 추가

buildFeatures{
    viewBinding true
}

 

3. ManinActivity.kt

첫번째 방법

class MainActivity : AppCompatActivity() {

    val binding by lazy {ActivityMainBinding.inflate(layoutInflater)}

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

        setContentView(binding.root)

        //setContentView(R.layout.activity_main)

        binding.radioGroup.setOnCheckedChangeListener{ _, checkedId ->
            Log.d("RadioButton", "radio 버튼 클릭")
            when(checkedId){
                R.id.radio1 -> binding.textView.text = "사과가 선택되었습니다."
                R.id.radio2 -> binding.textView.text = "바나나가 선택되었습니다."
                R.id.radio3 -> binding.textView.text = "오렌지가 선택되었습니다."
            }
        }
    }
}

 

두번째 방법

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

        val radioGroup = findViewById<RadioGroup>(R.id.radioGroup)
        val textView = findViewById<TextView>(R.id.textView)

        radioGroup.setOnCheckedChangeListener{ _, checkedId ->
            Log.d("RadioButton", "radio 버튼 클릭")
            when(checkedId){
                R.id.radio1 -> textView.text = "사과가 선택되었습니다."
                R.id.radio2 -> textView.text = "바나나가 선택되었습니다."
                R.id.radio3 -> textView.text = "오렌지가 선택되었습니다."
            }
        }
    }
}

 

결과물