RecyclerView exception using PreferenceFragmentCompat without any RecyclerView

Question

I am using PreferenceFragmentCompat and I get this runtime exception:

Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setAdapter(android.support.v7.widget.RecyclerView$Adapter)' on a null object reference

The confusing part is that my preference definition does not contain any RecyclerViews. Here is the XML:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.preference.PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android" >

<android.support.v7.preference.PreferenceCategory
    android:layout="@layout/preference_first_category"
    android:title="@string/pref_category_general">

    <android.support.v7.preference.SwitchPreferenceCompat
        android:title="@string/pref_demo_mode"
        android:key="@string/pref_demo_mode_key"
        android:defaultValue="true"
        android:persistent="true" />

</android.support.v7.preference.PreferenceCategory>

<android.support.v7.preference.PreferenceCategory
    android:layout="@layout/preference_category"
    android:key="serverCategory"
    android:persistent="false"
    android:title="@string/pref_category_server">

    <android.support.v7.preference.EditTextPreference
        android:title="@string/pref_server_control_ip"
        android:summary="@string/pref_enter_ip_address"
        android:defaultValue="@string/pref_enter_ip_address"
        android:key="@string/pref_ctrl_ip_key"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:persistent="true" />

    <android.support.v7.preference.EditTextPreference
        android:title="@string/pref_server_admin_ip"
        android:summary="@string/pref_enter_ip_address"
        android:defaultValue="@string/pref_enter_ip_address"
        android:key="@string/pref_admin_ip_key"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:persistent="true" />

    <android.support.v7.preference.EditTextPreference
        android:title="@string/pref_server_network_mask"
        android:defaultValue="@string/pref_enter_network_mask"
        android:summary="@string/pref_enter_network_mask"
        android:key="@string/pref_network_mask_key"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:persistent="true" />

</android.support.v7.preference.PreferenceCategory>         
</android.support.v7.preference.PreferenceScreen>

I have review the Reference API and can clearly see that PreferenceFragmentCompat does support RecyclerView but I have seen several examples of working code that do NOT have a RecyclerView view in their preferences so it appears RecyclerView is not mandatory.

Do I need to override any RecyclerView methods? Other working examples without RecyclerView didn't need to so I am at a loss as to how to resolve this.

Thanks, -Andres

Answer 1

Leaving this answer for anyone who stumbles upon it: I had this same problem. In my case the issue was that I had this:

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_settings, container, false);
    }

Once I commented this out it worked: evidently PreferenceCompatFragment must inflate its own view (that probably provides the RecyclerView). If you override it and inflate your own layout it will fail.