How to open same Activity with different data in Android Kotlin?

Question

class FirstActivity : AppCompatActivity() {
    companion object{
        val USER_KEY="FirstActivity"
    }


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

        button_firstActivity.setOnClickListener {
            val string:String=textView_first.text.toString()

            val intent=Intent(this,MainActivity::class.java)

            intent.putExtra(USER_KEY,string)
            startActivity(intent)
        }
    }
}


class MainActivity : AppCompatActivity() {
    companion object{
        val MAINUSERKEY="MainActivity"
        var str:String=""
    }


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

        str=intent.getStringExtra(FirstActivity.USER_KEY)

        textview_main.text=str

        button_Run.setOnClickListener {
            val edittextstring=editText1.text.toString()
            val intent=Intent(this,MainActivity::class.java)
            intent.putExtra(MAINUSERKEY,edittextstring)
            startActivity(intent)
        }
    }
}

Hello every one! I am new to Android programming with Kotlin.

I have two activities, suppose A and B. I want to start activity B from A and when B starts, it will display the TextView string of A into TextView_Main.

It is working fine now. I want to start activity B again on clicking button_Run which is on Activity B and passing a string again which I entered in edittext of Activity B. And now it should be displayed on textview of Activity B, when it opens again.

Please help me do this.

Answer 1

The problem is that the edittext string is being stored as an intent extra with name MAINUSERKEY="MainActivity”, which is different from the extra you are currently extracting on your MainActivity, the one with name USER_KEY="FirstActivity”. So I would do something like this to ensure I get the correct string extra:

str = with(intent) {
     getStringExtra(FirstActivity.USER_KEY) ?: getStringExtra(MainActivity.MAINUSERKEY) ?: "No string extra was found"
}