在创建片段视图后设置选项菜单对我来说效果很好。

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    setHasOptionsMenu(true);        
}

如果上面的选项都不适合你，在你的片段中试试这个:

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setHasOptionsMenu(true)
    }


    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { 
....
        toolBar = rootView.findViewById(R.id.import_contacts_toolbar)
        toolBar?.title = "Your title"
        toolBar?.subtitle = "yor subtitile"
        contactsActivity().setSupportActionBar(toolBar)
        toolBar?.inflateMenu(R.menu.import_contacts_menu)
...
}



    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.1 -> {

                return true
            }
            R.id.2 -> {

                return true
            }
        }
    
        return false
    }





    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        menu.clear()
        inflater.inflate(R.menu.import_contacts_menu, menu)
        super.onCreateOptionsMenu(menu, inflater)

        val search = menu.findItem(R.id.action_search)
        val searchView = search.actionView as SearchView
        searchView.requestFocus()

        val txtSearch = searchView.findViewById<View>(androidx.appcompat.R.id.search_src_text) as EditText
        txtSearch.hint = "Search..."
        txtSearch.setHintTextColor(Color.WHITE);
        txtSearch.setTextColor(Color.WHITE)

        try {
            val f: Field = TextView::class.java.getDeclaredField("mCursorDrawableRes")
            f.setAccessible(true)
            f.set(txtSearch, R.drawable.search_edit_text_cursor)
        } catch (ignored: Exception) {
            Log.d(TAG, "failed to expose cursor drawable $ignored")
        }

        searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
            override fun onQueryTextSubmit(query: String): Boolean {
                return false
            }

            override fun onQueryTextChange(newText: String): Boolean {

                return true
            }
        })
        searchView.setOnCloseListener {
            
        }
    }

在我的例子中，我有一个搜索菜单项，它被设置为始终可见。这是它的xml文件:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <item
        android:id="@+id/action_search"
        app:showAsAction="always"
        app:actionViewClass="androidx.appcompat.widget.SearchView"
        android:title="Search"/>

    <item android:id="@+id/1"
        android:title="1">
    </item>

    <item android:id="@+id/2"
        android:title="2">
    </item>
</menu>

调用super方法:

Java:

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // TODO Add your menu entries here
        super.onCreateOptionsMenu(menu, inflater);
    }

科特林：

    override fun void onCreate(savedInstanceState: Bundle) {
        super.onCreate(savedInstanceState)
        setHasOptionsMenu(true)
    }

    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        // TODO Add your menu entries here
        super.onCreateOptionsMenu(menu, inflater)
    }

在代码中放入日志语句，以查看是否没有调用该方法，或者您的代码是否没有修改菜单。

同时确保你在onCreate(Bundle)中调用sethasoptionmenu (boolean)来通知片段它应该参与选项菜单处理。

我的问题略有不同。我做的一切都是对的。但是我为承载片段的活动继承了错误的类。

所以要清楚，如果你在片段中重写onCreateOptionsMenu(菜单菜单，MenuInflater inflater)，确保你的活动类承载这个片段继承android.support.v7.app。ActionBarActivity(如果你想要支持低于API级别11)。

我继承了android.support.v4.app。FragmentActivity支持API级别低于11。

你的代码很好。方法中只少了super:

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // TODO add your menu : 
    inflater.inflate(R.menu.my_menu, menu);
    //TODO call super
    super.onCreateOptionsMenu(menu, inflater);
}

在菜单文件夹中创建一个.menu xml文件，并添加这个xml文件

<item
    android:id="@+id/action_search"
    android:icon="@android:drawable/ic_menu_search"
    android:title="@string/action_search"
    app:actionViewClass="android.support.v7.widget.SearchView"
    app:showAsAction="always|collapseActionView" />

在您的片段类中重写此方法和

implement SearchView.OnQueryTextListener    in your fragment class



@Override
 public void onViewCreated(View view, Bundle savedInstanceState) {    
  super.onViewCreated(view, savedInstanceState);
  setHasOptionsMenu(true);

}

现在只需在fragment class中设置你的菜单xml文件

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.menu_main, menu);

    final MenuItem item = menu.findItem(R.id.action_search);
    final SearchView searchView = (SearchView)    
    MenuItemCompat.getActionView(item);


    MenuItemCompat.setOnActionExpandListener(item,
            new MenuItemCompat.OnActionExpandListener() {
                @Override
                public boolean onMenuItemActionCollapse(MenuItem item) {
                    // Do something when collapsed

                    return true; // Return true to collapse action view
                }

                @Override
                public boolean onMenuItemActionExpand(MenuItem item) {
                    // Do something when expanded
                    return true; // Return true to expand action view
                }
            });

}