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onCreate方法上添加setHasOptionMenu()
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
然后覆盖你的onCreateOptionsMenu
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
menu.add("Menu item")
.setIcon(android.R.drawable.ic_delete)
.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
}
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
在onCreate方法上添加setHasOptionMenu()
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
然后覆盖你的onCreateOptionsMenu
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
menu.add("Menu item")
.setIcon(android.R.drawable.ic_delete)
.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
}
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;
}
