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

Answer 2

it is more clear to startActivity like code below, add this code in ActivityB
companion object{
private const val EXTRA_ MAIN_USERKEY = "EXTRA.MAIN_USERKEY"
fun getIntent(context:Context, userKey:String): Intent
{
val intent = Intent(context,ActivityB::class.java)
intent.putExtra(EXTRA_ MAIN_USERKEY, userKey)
return intent
}
}
and this code in ActivityA:
startActivity(ActivityB.getIntent(this,"some key"))
so every time you start activityB you should pass the string