how to handle back pressed in Kotlin

Question

my app having only two base activity and several fragment,, i want to display an Exit alert when user reach particular base fragment by clicking back press

override fun onBackPressed() {
        if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
          drawer_layout.closeDrawer(GravityCompat.START)

        } else {
         // super.onBackPressed()
            AlertDialog.Builder(this)
                .setTitle("Exit Alert")
                .setMessage("Do You Want To Exit Petals App?")
                .setPositiveButton(android.R.string.ok) { dialog, whichButton ->
                    super.onBackPressed()
                }
                .setNegativeButton(android.R.string.cancel) { dialog, whichButton ->

                }
                .show()

        }

i used addtosatck on each fragment

so you want to show this alert only in specific fragment? – Vladyslav Matviienko Jul 10 '19 at 07:12 — Vladyslav Matviienko, Jul 10 '19 at 07:12

IntelliJ Amiya · Accepted Answer · 2019-07-10T07:51:25.690

At first Check Visible Fragment

val currentFragment =this@ActivityName.supportFragmentManager.findFragmentById(R.id.Your_id)
        if(currentFragment is FragmentName)
        {
         // AlertDialog()
        }

Finally

override fun onBackPressed() 
{
        if (drawer_layout.isDrawerOpen(GravityCompat.START)) {
          drawer_layout.closeDrawer(GravityCompat.START)

        } else 
        {

            val currentFragment =this@ActivityName.supportFragmentManager.findFragmentById(R.id.Your_id)
            if(currentFragment is SpecificFragmentName)
            {
               AlertDialog.Builder(this@ActivityName)
                    .setTitle("Exit Alert")
                    .setMessage("Do You Want To Exit Petals App?")
                    .setPositiveButton(android.R.string.ok) { dialog, whichButton ->
                        super.onBackPressed()
                    }
                    .setNegativeButton(android.R.string.cancel) { dialog, whichButton ->

                    }
                    .show()
            }
            else{
            super.onBackPressed()
            }


    }
}

onBackPressed() is deprecated. Are there any alternatives to handle the back click? — Abdulrahman Hasanato, May 03 '23 at 08:48
@AbdulrahmanHasanato https://stackoverflow.com/questions/72634225/onbackpressed-deprecated-what-is-the-alternative — IntelliJ Amiya, May 05 '23 at 07:20

score 0 · Answer 2 · answered Feb 12 '20 at 09:20

0

You can just:

    val callback = requireActivity().onBackPressedDispatcher.addCallback(this) {
        // Handle the back button event
    }

For more information you can check this.

answered Feb 12 '20 at 09:20

solaza

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how to handle back pressed in Kotlin

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