Bump into NullPointerExeption when calling AlertDialog.getButton(AlertDialog.BUTTON_POSITIVE)
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setEnabled(boolean)' on a null object referenceWell, you can only access getButton after AlertDialog.show is called.
If you are using DialogFragment, you can access the button at onStart.
class LocationPickerDialog : DialogFragment() { private val okButton: Button by lazy { (dialog as AlertDialog).getButton(AlertDialog.BUTTON_POSITIVE) } private val cancelButton: Button by lazy { (dialog as AlertDialog).getButton(AlertDialog.BUTTON_NEGATIVE) } override fun onCreateDialog(savedInstanceState: Bundle?): Dialog { val customView = activity!!.layoutInflater.inflate(R.layout.dialog_location_picker, null) val builder = AlertDialog.Builder(context!!) // .setTitle(title) // .setMessage("Do Something!") .setView(customView) /* .setPositiveButton(android.R.string.ok) { _, _ -> // do something } .setNegativeButton(android.R.string.cancel) { _, _ -> // do something } */ .setPositiveButton(android.R.string.ok, null) .setNegativeButton(android.R.string.cancel, null) val dialog = builder.create() // access button here will trigger NullPointerException // val okButton = dialog.getButton(AlertDialog.BUTTON_POSITIVE) // okButton.isEnabled = false return dialog } override fun onStart() { super.onStart() okButton.setOnClickListener { // do something } cancelButton.setOnClickListener { // do something } okButton.isEnabled = false cancelButton.isEnabled = false }}NOTE: You can access the button at dialog.setOnShowListener callback as well.