Press a button to execute an operation instead of using back button

Issue

I am selecting an image from gallery.

When I press the back button, the getResultCamera.launch(intent) is called and an operation takes place.

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

        image = findViewById(R.id.the_selected_image);
        srButton = findViewById(R.id.super_resolution_button)

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED) {
                val permissions = arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE)
                requestPermissions(permissions, PERMISSION_CODE)
            } else {
                chooseImageGallery()
            }
        } else {
            chooseImageGallery()
        }


    }


private fun chooseImageGallery() {
        val intent = Intent(Intent.ACTION_PICK)
        intent.type = "image/*"
        getResultCamera.launch(intent)
    }


 private val getResultCamera =
        registerForActivityResult(
            ActivityResultContracts.StartActivityForResult()
        ) {
            if (it.resultCode == Activity.RESULT_OK) {
                imageUri = it.data?.data as Uri
                image.setImageURI(imageUri)
                intent.putExtra("imageuri", imageUri)
                

            }
        }

So, it goes to the MainActivity, it loads the image and the operation takes place there.

Now, I want to use a button for the user to press instead of the back button.

So, I am trying something like:

private val getResultCamera =
        registerForActivityResult(
            ActivityResultContracts.StartActivityForResult()
        ) {
            if (it.resultCode == Activity.RESULT_OK) {
                imageUri = it.data?.data as Uri
                image.setImageURI(imageUri)
                
                srButton.setOnClickListener { view: View ->
                    intent.putExtra("imageuri", imageUri)
                    val intent = Intent(this, MainActivity::class.java)
                    startActivity(intent)
                }

            }
        }

but when I press the button, it just returns to the MainActivity without executing the operation.

Solution

Try putting finish() in the button's OnClickListener. This basically acts as though the user pressed the back button.

Answered By - HapaxLegomenon