Disable Android menu group

Question

I try to disable a menu group with the following code, but it doesn't work, menu items are still enabled. Can you tell me what's wrong please?

res/menu/menu.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:id="@+id/a" android:title="A"></item>
  <item android:id="@+id/b" android:title="B">
    <menu>
      <item android:id="@+id/c" android:title="C" />
      <item android:id="@+id/d" android:title="D" />
      <group android:id="@+id/group_1">
        <item android:id="@+id/e" android:title="E" />
        <item android:id="@+id/f" android:title="F" />
      </group>
    </menu>
  </item>
</menu>

Java:

public boolean onPrepareOptionsMenu (Menu menu) {
    menu.setGroupEnabled (R.id.group_1, false); // does not work
    menu.setGroupVisible (R.id.group_1, false); // does not work either
    return super.onPrepareOptionsMenu (menu);
}

public boolean onCreateOptionsMenu (Menu menu) {
    getMenuInflater ().inflate (R.menu.menu, menu);
    return true;
}

Answer 1

Thanks to user432209's info, here is the answer:

menu.findItem (R.id.b).getSubMenu ().setGroupVisible (R.id.group_1, false);

Answer 2

I'm not sure if you can use a group like this, but try this (its worth a shot):

MenuItem item = menu.findItem(R.id.group_1);
item.setVisible(true);
item.setEnabled(false);

Edit: Your problem is your menu structure and how you create the menu inside onCreateOptionsMenu due to using parent/child menus.

You create a menu for the parent menu, not the child menu, so that is why the call to setGroupEnabled and setGroupVisible fail. You need to create an object in onCreateOptionsMenu that represents the child in order for that object to be passed into onPrepareOptionsMenu and your code to work.