除此之外，我还要补充一件事，以及它不适合我的原因。

这与Napster的答案相似。

Make sure your fragment's hosting activity extends AppCompatActivity, not FragmentActivity! public class MainActivity extends AppCompatActivity { } From the Google Reference Documentation for FragmentActivity: Note: If you want to implement an activity that includes an action bar, you should instead use the ActionBarActivity class, which is a subclass of this one, so allows you to use Fragment APIs on API level 7 and higher. To update Napster's answer -- ActionBarActivity now being deprecated, use AppCompatActivity instead. When using AppCompatActivity, also make sure you set "the activity theme toTheme.AppCompat or a similar theme" (Google Doc).

注意:android.support.v7.app。AppCompatActivity是android.support.v4.app的子类。FragmentActivity类(参见AppCompatActivity ref doc)。

在膨胀菜单之前，您需要使用menu.clear()。

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

and

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

这是我所做的隐藏和取消隐藏所有的菜单选项时，片段分别被加载和销毁。它避免了将R.id指向null的风险。Your_menu_item并允许我在其他地方重用这个片段。

lateinit var optionsMenu: Menu

override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
    menu.iterator().forEach {
        it.isVisible = false
    }
    optionsMenu = menu
    super.onCreateOptionsMenu(menu, inflater)
}

override fun onDestroyView() {
    optionsMenu.iterator().forEach {
        it.isVisible = true
    }
    super.onDestroyView()
}

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);        
}

在我的例子中，下面是步骤。

步骤1

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Here notify the fragment that it should participate in options menu handling.
    setHasOptionsMenu(true);
}

步骤2

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // First clear current all the menu items
    menu.clear();

    // Add the new menu items
    inflater.inflate(R.menu.post_stuff, menu);

    super.onCreateOptionsMenu(menu, inflater);
}

步骤3

 @Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.post_stuff:
            Log.d(TAG, "Will post the photo to server");
            return true;
        case R.id.cancel_post:
            Log.d(TAG, "Will cancel post the photo");
            return true;
        default:
            break;
    }
    return super.onOptionsItemSelected(item);
}

我也遇到了同样的问题，但我认为最好总结并介绍让它工作的最后一步:

在Fragment的onCreate(Bundle savedInstanceState)方法中添加sethasoptionmenu (true)方法。 重写onCreateOptionsMenu(菜单菜单，MenuInflater膨胀器)(如果你想做一些不同的在你的片段的菜单)和onOptionsItemSelected(MenuItem项目)方法在你的片段。 在onOptionsItemSelected(MenuItem item) Activity的方法中，当菜单项操作将在onOptionsItemSelected(MenuItem item) Fragment的方法中实现时，确保返回false。

一个例子:

活动

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getSupportMenuInflater();
    inflater.inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {

        case R.id.activity_menu_item:

            // Do Activity menu item stuff here
            return true;

        case R.id.fragment_menu_item:

            // Not implemented here
            return false;
        default:
            break;
    }

    return false;
}

片段

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

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // Do something that differs the Activity's menu here
    super.onCreateOptionsMenu(menu, inflater);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {

        case R.id.activity_menu_item:

            // Not implemented here
            return false;
        case R.id.fragment_menu_item:

            // Do Fragment menu item stuff here
            return true;

        default:
            break;
    }

    return false;
}