[Kotlin] How to Resolve the Deprecate of onBackPressed

• How to Resolve the Deprecate of onBackPressed
• OnBackPressedCallback
• 테스트 전체 소스
  • AndroidManifest.xml
  • activity_from.xml
  • FromActivity.kt

 

How to Resolve the Deprecate of onBackPressed

onBackPressed의 deprecated

 API 33부터는 onBackPressed가 deprecated가 되어 더 이상 호출되지 않습니다. 때문에 이를 해결할 방법이 필요합니다.

 

OnBackPressedCallback

이를 해결하기 위해서는 이제 override 함수가 아닌 callback 선언을 통하여 사용해주어야 합니다.

// back key 처리를 위한 handler 선언
private val hndlBackPress = object:OnBackPressedCallback(true) {
    override fun handleOnBackPressed() {
        Log.d("hndlBackPress", "back key pressed!!")
    }
}

이후 onCreate에서 이를 연결해 주면, back key를 누를 때마다 선언된 hndlBackPress가 실행되게 됩니다.

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_to)

    this.onBackPressedDispatcher.addCallback(this, hndlBackPress)
}

Log창에 출력 된 Back 키 결과

 

테스트 전체 소스

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/Theme.Kotlin"
        tools:targetApi="31">

        <!-- FromActivity.kt 선언. 메인 페이지 (실행 시 처음 뜨는 Activity) -->
        <activity
            android:name=".FromActivity"
            android:exported="true"
            android:label="@string/app_name"
            android:theme="@style/Theme.Kotlin.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

activity_from.xml

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

    <Button
        android:id="@+id/btnNext"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="NEXT"
        />
</RelativeLayout>

FromActivity.kt

package net.royfactory.kotlin

import android.os.Bundle
import android.util.Log
import androidx.activity.OnBackPressedCallback
import androidx.appcompat.app.AppCompatActivity

class FromActivity : AppCompatActivity() {
    private val hndlBackPress = object: OnBackPressedCallback(true) {
        override fun handleOnBackPressed() {
            Log.d("hndlBackPress", "back key pressed!!")
        }
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_from)

        this.onBackPressedDispatcher.addCallback(this, hndlBackPress)
    }
}