Can I change what the back arrow at the bottom of the screen does?

Question

Can I change what that button does. I tried just using it but when the user changes something and goes back, the changes aren't applied

Use the edit link under your question to fill out the tags appropriately. — LarsTech, Mar 14 '20 at 21:44

score 0 · Answer 1 · answered Mar 14 '20 at 21:56

0

It's very easy, just override onBackPress of your activity. Check documentation for more info - https://developer.android.com/reference/android/app/Activity#onBackPressed()

answered Mar 14 '20 at 21:56

Alex Grebennikov

170
5
11

So for every activity, is there a onBackPress function? – Abdallah Alqashqish Mar 14 '20 at 22:20
I've tried overriding the onBackPress. It gives me an error saying "Annotations are not allowed here" – Abdallah Alqashqish Mar 14 '20 at 22:40
1st comment - yes. 2nd comment - can you provide your code? seems like it is not the method override problem – Alex Grebennikov Mar 16 '20 at 05:25
1

Oh, I figured it out. The problem was that I was trying to override it in the onCreate() method. Now it works. Thank you. – Abdallah Alqashqish Mar 18 '20 at 16:06

score 0 · Answer 2 · answered Mar 14 '20 at 22:00

0

Did you search for it?

Android - How To Override the "Back" button so it doesn't Finish() my Activity?

you can override onBackPressed() method in your activity

answered Mar 14 '20 at 22:00

Erfan

83
4
9

score 0 · Answer 3 · answered Mar 15 '20 at 05:06

Try this simple code:

import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

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

    override fun onBackPressed() {
      //  super.onBackPressed()
        Toast.makeText(this,"Back Pressed",Toast.LENGTH_LONG).show()
    }

}

Can I change what the back arrow at the bottom of the screen does?

3 Answers3