[Android Studio] StartActivityForResult, OnActivityResult method is deprecated (Kotlin)

[해결방법]

1. 변수를 하나 생성하고 registerForActivityResult(ActivityResultContracts.StartActivityForResult( )){ }를 대입

 

2. 중괄호 안에 기존의 onActivityResult( )에서 수행했던 코드를 넣음

 

val getAction = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){
    val message = it.data?.getStringExtra("returnValue")
    Toast.makeText(this, message, Toast.LENGTH_LONG).show()
}

 

3. startActivityForReslut(intent) 대신에 1번에서 생성한 변수.launch(intent)로 교체

 

binding.btnStart.setOnClickListener { 

    getAction.launch(intent)
}

 

[The old way]

class MainActivity : AppCompatActivity() {

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

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        // deprecated
        if(resultCode == RESULT_OK){
            when(requestCode){
                99 -> {
                    val message = data?.getStringExtra("returnValue")
                    Toast.makeText(this,message,Toast.LENGTH_LONG).show()
                }
            }
        }
    }

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

        val intent = Intent(this, SubActivity::class.java)
        intent.putExtra("from1","Hello Bundle")
        intent.putExtra("from2", 2021)
        binding.btnStart.setOnClickListener {
            startActivityForResult(intent, 99)
            // deprecated
        }  
    }
}

[The new way - kotlin]

class MainActivity : AppCompatActivity() {

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

    /*
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    //super.onActivityResult(requestCode, resultCode, data)
    // deprecated
        if(resultCode == RESULT_OK){
            when(requestCode){
                99 -> {
                    val message = data?.getStringExtra("returnValue")
                    Toast.makeText(this,message,Toast.LENGTH_LONG).show()
                }
            }
        }
    }
*/

 

    val getAction = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){
        val message = it.data?.getStringExtra("returnValue")
        Toast.makeText(this, message, Toast.LENGTH_LONG).show()
    }

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

        val intent = Intent(this, SubActivity::class.java)
        intent.putExtra("from1","Hello Bundle")
        intent.putExtra("from2", 2021)
        binding.btnStart.setOnClickListener {
/*
            startActivityForResult(intent, 99)
            // deprecated
*/
            getAction.launch(intent)
        }
    }
}

한글로는 아래에 설명이 잘 되어 있는듯
https://modelmaker.tistory.com/18