How to force action bar overflow icon to show

I would like to force the overflow icon to always show in the action bar (assuming there are overflow items). On models with a menu button, sometimes the overflow icon doesn‘t appear and users must tap the devices menu button to get the rest of the action menu items. Users keep complaining about this.

Note that for the context menu, the overflow icon always shows, regardless of whether the device has a built in menu button or not.

I realize that forcing the overflow icon to appear in the action bar would duplicate the functionality of the "physical" one. You might consider that violating Androids design guidelines. In my opinion, though, the users win. They say it‘s confusing and I believe they‘re right.

Congratulations! You won!

As of Android 4.4, the ... affordance in the action bar will be there, regardless of whether the device has a physical MENU button or not. Google‘s current Compatibility Definition Document now comes out a bit more forcefully against having a dedicated MENU button.

The hack that developers have used in the past, to get this behavior, is:

try { 
  ViewConfiguration config = ViewConfiguration.get(this);
  Field menuKeyField = ViewConfiguration.class.getDeclaredField("sHasPermanentMenuKey");
 
  if (menuKeyField != null) {
    menuKeyField.setAccessible(true);
    menuKeyField.setBoolean(config, false);
  } 
} 
catch (Exception e) {
  // presumably, not relevant 
}

That should not be needed on Android 4.4+, though with the exception handler in place, I would not expect any particular problem if you run it and, someday, they get rid of sHasPermanentMenuKeyoutright.

Personally, I still wouldn‘t change things on Android 4.3 and below, as I suspect it‘s a whack-a-mole situation, where you will replace complaints about having no menu with complaints about having duplicate versions of the same menu. That being said, since this is now the officially endorsed behavior going forward, I have no problems with developers aiming for consistency on older devices.

A hat tip to the commenter on the issue I filed regarding this, pointing out the change.

This could be another work around, which really helped me. Keep one drawable with three dots and give it as a menu item.

<item
    android:id="@+id/saveDetails"
    android:showAsAction="always"
    android:title="@string/save"/>

<item
    android:id="@+id/menu_overflow"
    android:icon="@drawable/dts"
    android:orderInCategory="11111"
    android:showAsAction="always">
    <menu>
        <item
            android:id="@+id/contacts"
            android:showAsAction="never"
            android:title="Contacts"/>


        <item
            android:id="@+id/service_Tasks"
            android:showAsAction="never"
            android:title="Service Tasks"/>


        <item
            android:id="@+id/charge_summary"
            android:showAsAction="never"
            android:title="Charge Summary"/>


        <item
            android:id="@+id/capture_signature"
            android:showAsAction="never"
            android:title="Capture Signature"/>
    </menu>
</item>

</menu>

How to force action bar overflow icon to show

原文：http://my.oschina.net/artshell/blog/393108