Android - prevent WebView from reloading when going back and forth

Question

I have Activity A and Activity B in my Android App. In Activity A there is a button which leads to Activity B. In the Activity B I have a WebView with Internet Form. The user can enter some data into that form. If he goes back to Activity A and then again to Activity B he will loose that entered data. How can I prevent this from happeing?

Answer 1

Firstly, you would need to add android:launchMode="singleInstance" to both the activities in the manifest. This will ensure if an instance of an activity exists, then it will bring it forward and call its onNewIntent() function rather than creating a new activity and calling its onCreate().

You could start Activity B from Activity A and make sure to NOT use finish().

For example in Activity A: startActivity(Intent(this, ActivityB::class.java))

When the user wants to go back to Activity A from Activity B make sure to call startActivity(Intent(this, ActivityA::class.java)) This would require you to override the hardware back button behaviour and maybe also the navigation back button if you are showing that as well. Kotlin example:

    /* Top navigation button */
    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        if (item.itemId == android.R.id.home) {
            finish()
            return true
        }
        return super.onOptionsItemSelected(item)
    }

    /* Hardware back button */
    override fun onBackPressed() {
        startActivity(Intent(this, MainActivity::class.java))
    }