Cannot resolve symbol 'onRadioButtonClicked' - android-studio

Question

Android: onClick = "onRadioButtonClicked" has the same name as the function. I can not understand why he does not recognize it.
The poblem is in xml file, " Cannot resolve symbol 'onRadioButtonClicked' " on the Android: onClick = "onRadioButtonClicked" line
I followed this
My xml file
<RadioGroup
android:id="#+id/radioGroupLag"
android:checkedButton="#+id/radioButtonEnglish">
<TextView
android:id="#+id/textView_lang"
android:text="#string/txt_language"
android:textSize="20sp"
android:textStyle="bold"/>
<RadioButton
android:id="#+id/radioButtonGreek"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/RadioButtonGreek"
android:onClick= "onRadioButtonClicked"
android:textSize="20sp"
/>
<RadioButton
android:id="#+id/radioButtonEnglish"
android:text="#string/RadioButtonEnglish"
android:onClick= "onRadioButtonClicked"/>
<RadioButton
android:id="#+id/radioButtonGerman"
android:text="#string/RadioButtonGerman"
android:onClick= "onRadioButtonClicked"/>
</RadioGroup>
My fun in the Fragment:
private fun onRadioButtonClicked(view: View) {
if (view is RadioButton) {
val checked = view.isChecked
// Check which radio button was clicked
when (view.getId()) {
R.id.radioButtonGreek->{
if (checked) {
changeLag()
}
}
R.id.radioButtonGerman ->{
if (checked) {
changeLag()
}
}
R.id.radioButtonEnglish-> {
if (checked) {
changeLag()
}
}
}
}
}
End i call the fun in onCreateView
onRadioButtonClicked(binding.radioGroupLag)

Answer 1

The method you declare in the android:onClick attribute must have a signature exactly as shown above. Specifically, the method must:
Be public
Return void
Define a View as its only parameter (this will be the View that was clicked)
Quote from the guide you linked (emphasis mine). Make your method public.