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menu.xml中，您应该添加所有菜单项。然后，您可以隐藏您不想在初始加载中看到的项目。

menu。xml

<item
    android:id="@+id/action_newItem"
    android:icon="@drawable/action_newItem"
    android:showAsAction="never"
    android:visible="false"
    android:title="@string/action_newItem"/>

在onCreate()方法中添加sethasoptionsmmenu (true)来调用Fragment类中的菜单项。

FragmentClass.java

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

你不需要在你的Fragment类中重写onCreateOptionsMenu。菜单项可以通过重写Fragment中可用的onprepareoptionmenumethod来更改(添加/删除)。

@Override
public void onPrepareOptionsMenu(Menu menu) {
    menu.findItem(R.id.action_newItem).setVisible(true);
    super.onPrepareOptionsMenu(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。

菜单文件:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/play"
        android:titleCondensed="Speak"
        android:showAsAction="always"
        android:title="Speak"
        android:icon="@drawable/ic_play">
    </item>
    <item
        android:id="@+id/pause"
        android:titleCondensed="Stop"
        android:title="Stop"
        android:showAsAction="always"
        android:icon="@drawable/ic_pause">
    </item>
</menu>

活动代码:

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

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

        case R.id.play:
            Toast.makeText(getApplicationContext(), "speaking....", Toast.LENGTH_LONG).show();
            return false;

        case R.id.pause:
            Toast.makeText(getApplicationContext(), "stopping....", Toast.LENGTH_LONG).show();
            return false;

        default:
            break;
    }

    return false;
}

片段代码:

@Override

public void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}

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

        case R.id.play:
            text = page.getText().toString();
            speakOut(text);

            // Do Activity menu item stuff here
            return true;

        case R.id.pause:
            speakOf();

            // Not implemented here
            return true;

        default:
            break;
    }
    return false;
}

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);
}

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);
}