我试图从一组片段中添加一个项目到选项菜单。
我已经创建了一个新的MenuFragment类，并扩展了我希望包含菜单项的片段。代码如下:
Java:
public class MenuFragment extends Fragment {
MenuItem fav;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
fav = menu.add("add");
fav.setIcon(R.drawable.btn_star_big_off);
}
}
科特林：
class MenuFragment : Fragment {
lateinit var fav: MenuItem
override fun onCreate(savedInstanceState: Bundle) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
fav = menu.add("add");
fav.setIcon(R.drawable.btn_star_big_off);
}
}
由于某种原因，onCreateOptionsMenu似乎没有运行。
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
}
});
}
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)。
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。
