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);
}
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;
}
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)。
自androidx.activity:activity:1.4.0以来，有了一种新的方法来做到这一点
你应该使用菜单提供者API。
它的用法如下:
而不是叫super。setHasOptionMenu和实现oncreateoptionmenu你应该在onViewCreated中调用addMenuProvider。
一个例子:
class ExampleFragment : Fragment(R.layout.fragment_example) {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
// The usage of an interface lets you inject your own implementation
val menuHost: MenuHost = requireActivity()
// Add menu items without using the Fragment Menu APIs
// Note how we can tie the MenuProvider to the viewLifecycleOwner
// and an optional Lifecycle.State (here, RESUMED) to indicate when
// the menu should be visible
menuHost.addMenuProvider(object : MenuProvider {
override fun onCreateMenu(menu: Menu, menuInflater: MenuInflater) {
// Add menu items here
menuInflater.inflate(R.menu.example_menu, menu)
}
override fun onMenuItemSelected(menuItem: MenuItem): Boolean {
// Handle the menu selection
return true
}
}, viewLifecycleOwner)
}
来源:活动变更日志
