如何在PreferenceFragment之外修改Androidx Preference数据？

Question

I am trying to implement a custom Radio-style Preference where the user can click an option which is then assigned as the new value of the Preference :

Here is my layout:

preferences.xml

<Preference
    android:layout="@layout/preference_gender"
    android:key="seeking"
    android:title="Seeking"/>

preference_gender.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout>

<RadioGroup
    android:id="@+id/gender_group"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.appcompat.widget.AppCompatTextView
        ...
        android:text="@string/seeking"/>

    <androidx.appcompat.widget.AppCompatRadioButton
        android:id="@+id/male"
        android:text="Male"
        />

    <androidx.appcompat.widget.AppCompatRadioButton
        android:id="@+id/female"
        android:text="Female"
        />

    <androidx.appcompat.widget.AppCompatRadioButton
        android:id="@+id/both"
        android:text="Both"
        />

</RadioGroup>

</androidx.constraintlayout.widget.ConstraintLayout>

Because Preference.OnPreferenceClickListener can't detect specific clicks inside the Preference (only the preference as a whole), I've resorted to adding an onClick() function in the xml which is then passed to my activity:

then to my preferences fragment:

class PreferencesFragment : PreferenceFragmentCompat(), View.OnClickListener, RadioGroup.OnCheckedChangeListener {

    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
        setPreferencesFromResource(R.xml.preferences, rootKey)
    }


override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    gender_group.setOnCheckedChangeListener(this) // null pointer exception
}


}

however I get a NullPointerException on my findPreference("seeking")!! .

Is there any way around this?

Answer 1

preference_gender.xml has no Preference keys at all. A styled RadioGroup & 3 RadioButton might rather be suitable to represent those buttons below a single Preference key; nodes alike that AppCompatTextView might be rendered - but won't be treated alike a Preference would be.