build.gradle

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-android-extensions' // unutma 
}

     
     implementation 'androidx.activity:activity-ktx:1.3.0-alpha07'
     implementation 'androidx.fragment:fragment-ktx:1.3.3'

MainActivity.kt

class MainActivity : AppCompatActivity() {
    lateinit var binding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.btnGo.setOnClickListener {
            customContract.launch(User("Hamurcu", 26))
        }
        binding.btnPickImage.setOnClickListener {
            pickImage.launch("image/*")
        }
        binding.btnMultiPerm.setOnClickListener {
            askMultiplePermissions.launch(arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.CAMERA))
        }
    }

    private val customContract = registerForActivityResult(SimpleContract()) { data ->
        binding.textView.text = data
    }
    private val requestPermission = registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
        binding.textView.text = granted.toString()
    }
    private val askMultiplePermissions =
            registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { map ->
                for (entry in map.entries) {
                    Toast.makeText(this, "${entry.key} = ${entry.value}", Toast.LENGTH_SHORT).show()
                }
            }
    private val pickImage =
            registerForActivityResult(ActivityResultContracts.GetContent()) { uri ->
                binding.textView.text = uri?.toString()
            }
}

SecondActivity.kt

import android.content.Intent
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.emrehmrc.activitycontract.databinding.ActivitySecondBinding

class SecondActivity : AppCompatActivity() {

    lateinit var binding: ActivitySecondBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivitySecondBinding.inflate(layoutInflater)
        setContentView(binding.root)
        val user = intent.getParcelableExtra<User>(KEY_USER_OBJECT)
        binding.apply {
            txtUser.text = user.toString()
            btnSetResult.setOnClickListener { setResult() }
        }
    }

    private fun setResult() {
        val intent = Intent()
        intent.putExtra(KEY_RESULT, "Başarılııı!")
        setResult(RESULT_OK, intent)
        finish()
    }

}

SimpleContract.kt

import android.app.Activity
import android.content.Context
import android.content.Intent
import android.os.Parcelable
import androidx.activity.result.contract.ActivityResultContract
import kotlinx.android.parcel.Parcelize

//Create Custom Contract
const val KEY_USER_OBJECT = "KEY_USER_OBJECT"
const val KEY_RESULT = "RESULT"

@Parcelize
data class User(val name: String, val age: Int) : Parcelable

class SimpleContract : ActivityResultContract<User, String?>() {

    override fun createIntent(context: Context, input: User): Intent {
        val intent = Intent(context, SecondActivity::class.java)
        intent.putExtra(KEY_USER_OBJECT, input)
        return intent
    }

    override fun parseResult(resultCode: Int, intent: Intent?): String? = when {
        resultCode != Activity.RESULT_OK -> null
        else -> intent?.getStringExtra(KEY_RESULT)
    }
}