How to remove a preference from PreferenceActivity?

I'm using PreferenceActivity. How do I remove a preference? I cannot seem to get this to work:

Preference p = findPreference("grok");
boolean worked = getPreferenceScreen().removePreference(p);
// worked == false.

So the preference is found, but the removePreference() call fails. What's the right way to do this? I'm using a preference.xml file for the keys like so:

<PreferenceScreen
    xmlns:android="http://schemas.a开发者_运维知识库ndroid.com/apk/res/android">

    <PreferenceCategory
        android:title="foo">

        <CheckBoxPreference
            android:key="grok" />

            ...

Thanks

---

you can remove only exact child in PreferenceGroup. So in your case, you should add some key to PreferenceCategory (with title="foo"), then findPreference with this key & then remove it child

XML:

<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">

<PreferenceCategory
    android:key="category_foo"
    android:title="foo">

    <CheckBoxPreference
        android:key="grok" />

        ...

Code:

Preference p = findPreference("grok");
// removing Preference
((PreferenceGroup) findPreference("category_foo")).removePreference(p);

---

Instead of setting multiple ids, you can get the entire tree of preferences and find the parent of any preference, and then remove any of its children preferences:

public static Map<Preference,PreferenceGroup> buildPreferenceParentTree(final PreferenceActivity activity)
    {
    final Map<Preference,PreferenceGroup> result=new HashMap<Preference,PreferenceGroup>();
    final Stack<PreferenceGroup> curParents=new Stack<PreferenceGroup>();
    curParents.add(activity.getPreferenceScreen());
    while(!curParents.isEmpty())
      {
      final PreferenceGroup parent=curParents.pop();
      final int childCount=parent.getPreferenceCount();
      for(int i=0;i<childCount;++i)
        {
        final Preference child=parent.getPreference(i);
        result.put(child,parent);
        if(child instanceof PreferenceGroup)
          curParents.push((PreferenceGroup)child);
        }
      }
    return result;
    }

example:

  final Map<Preference,PreferenceGroup> preferenceParentTree=buildPreferenceParentTree(SettingsActivity.this);
  final PreferenceGroup preferenceParent=preferenceParentTree.get(preferenceToRemove);
  preferenceGroup.removePreference(preferenceToRemove);

---

EDIT: seems there is a new API for this :

https://developer.android.com/reference/androidx/preference/Preference#setVisible(boolean)

I'm not sure if currently it's available or not, though.