好吧，我对此很好奇，所以我深入挖掘了 SDK 的源代码。我在其 XML 文件中使用了 AppCompatActivity 和 3 个菜单项，并且我使用了默认的 onCreateOptionMenu 方法，即：
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
在我使用调试器从 inflate 方法继续前进后，我浏览了以下堆栈：
updateMenuView():96, BaseMenuPresenter (android.support.v7.internal.view.menu)
updateMenuView():231, ActionMenuPresenter (android.support.v7.widget)
dispatchPresenterUpdate():284, MenuBuilder (android.support.v7.internal.view.menu)
onItemsChanged():1030, MenuBuilder (android.support.v7.internal.view.menu)
startDispatchingItemsChanged():1053, MenuBuilder (android.support.v7.internal.view.menu)
preparePanel():1303, AppCompatDelegateImplV7 (android.support.v7.app)
doInvalidatePanelMenu():1541, AppCompatDelegateImplV7 (android.support.v7.app)
access$100():92, AppCompatDelegateImplV7 (android.support.v7.app)
run():130, AppCompatDelegateImplV7$1 (android.support.v7.app)
handleCallback():739, Handler (android.os)
dispatchMessage():95, Handler (android.os)
loop():148, Looper (android.os)
main():5417, ActivityThread (android.app)
invoke():-1, Method (java.lang.reflect)
run():726, ZygoteInit$MethodAndArgsCaller (com.android.internal.os)
main():616, ZygoteInit (com.android.internal.os)
它以BaseMenuPresenter的updateMenuView方法结束，这就是相关工作完成的地方。
方法的代码：
public void updateMenuView(boolean cleared) {
final ViewGroup parent = (ViewGroup) mMenuView;
if (parent == null) return;
int childIndex = 0;
if (mMenu != null) {
mMenu.flagActionItems();
ArrayList<MenuItemImpl> visibleItems = mMenu.getVisibleItems();
final int itemCount = visibleItems.size();
for (int i = 0; i < itemCount; i++) {
MenuItemImpl item = visibleItems.get(i);
if (shouldIncludeItem(childIndex, item)) {
final View convertView = parent.getChildAt(childIndex);
final MenuItemImpl oldItem = convertView instanceof MenuView.ItemView ?
((MenuView.ItemView) convertView).getItemData() : null;
final View itemView = getItemView(item, convertView, parent);
if (item != oldItem) {
// Don't let old states linger with new data.
itemView.setPressed(false);
ViewCompat.jumpDrawablesToCurrentState(itemView);
}
if (itemView != convertView) {
addItemView(itemView, childIndex);
}
childIndex++;
}
}
}
// Remove leftover views.
while (childIndex < parent.getChildCount()) {
if (!filterLeftoverView(parent, childIndex)) {
childIndex++;
}
}
}
这里的 getItemView 和 addItemView 方法按照他们的名字说的做。第一个膨胀一个新视图，第二个将它添加到父视图。更重要的是，在调试器下可以检查父对象，它是一个ActionMenuView，它继承自LinearLayout和膨胀形式abc_action_menu_layout.xml。
这意味着如果你能得到这个视图，你就可以做你想做的事。从理论上讲，我认为可以通过大量反思来完成，但这会很痛苦。
取而代之的是，您可以在代码中重现它。可以在here找到实现。
根据以上情况，你的问题的答案是YES，可以，但是会比较麻烦。
编辑：
我通过反射创建了一个概念证明。我用过com.android.support:appcompat-v7:23.1.0。
我已经在模拟器（Android 6.0）和我的 Zuk Z1（CM Android 5.1.1）上尝试过，两者都运行良好。
菜单 XML：
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item android:id="@+id/action_settings" android:title="@string/action_settings"
android:orderInCategory="100" app:showAsAction="always" />
<item android:id="@+id/action_settings2" android:title="TEST1"
android:orderInCategory="100" app:showAsAction="always" />
<item android:id="@+id/action_settings3" android:title="TEST2"
android:orderInCategory="100" app:showAsAction="always" />
</menu>
活动 XML：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Button"
android:id="@+id/button"
android:layout_gravity="center_vertical" />
</LinearLayout>
活动：
public class Main2Activity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//only a linear layout with one button
setContentView(R.layout.activity_main2);
Button b = (Button) findViewById(R.id.button);
// do the whole process for a click, everything is inited so we dont run into NPE
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AppCompatDelegate delegate = getDelegate();
Class delegateImpClass = null;
Field menu = null;
Method[] methods = null;
try {
//get objects based on the stack trace
delegateImpClass = Class.forName("android.support.v7.app.AppCompatDelegateImplV7");
//get delegate->mPreparedPanel
Field mPreparedPanelField = delegateImpClass.getDeclaredField("mPreparedPanel");
mPreparedPanelField.setAccessible(true);
Object mPreparedPanelObject = mPreparedPanelField.get(delegate);
//get delegate->mPreparedPanel->menu
Class PanelFeatureStateClass = Class.forName("android.support.v7.app.AppCompatDelegateImplV7$PanelFeatureState");
Field menuField = PanelFeatureStateClass.getDeclaredField("menu");
menuField.setAccessible(true);
Object menuObjectRaw = menuField.get(mPreparedPanelObject);
MenuBuilder menuObject = (MenuBuilder) menuObjectRaw;
//get delegate->mPreparedPanel->menu->mPresenter(0)
Field mPresentersField = menuObject.getClass().getDeclaredField("mPresenters");
mPresentersField.setAccessible(true);
CopyOnWriteArrayList<WeakReference<MenuPresenter>> mPresenters = (CopyOnWriteArrayList<WeakReference<MenuPresenter>>) mPresentersField.get(menuObject);
ActionMenuPresenter presenter0 = (ActionMenuPresenter) mPresenters.get(0).get();
//get the view from the presenter
Field mMenuViewField = presenter0.getClass().getSuperclass().getDeclaredField("mMenuView");
mMenuViewField.setAccessible(true);
MenuView menuView = (MenuView) mMenuViewField.get(presenter0);
ViewGroup menuViewParentObject = (ViewGroup) ((View) menuView);
//check the menu items count
int a = menuViewParentObject.getChildCount();
Log.i("ChildNum", a + "");
//set params as you want
Toolbar.LayoutParams params = (Toolbar.LayoutParams) menuViewParentObject.getLayoutParams();
params.gravity = Gravity.LEFT;
menuViewParentObject.setLayoutParams(params);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
}
虽然这里的重力发生了变化，但在屏幕上这并没有什么明显的区别。要获得真正可见的更改，应调整其他布局参数（例如 width ）。
总而言之，自定义布局更易于使用。