如何在片段中使用 setSupportActionBar

Question

我需要在我无法使用的片段中使用 setSupportActionBar 我也无法使用 setContentView 请帮助它也提前谢谢你 给出了相关代码

public class StudentrFragment extends Fragment {
        Toolbar toolbar;
        TabLayout tabLayout;
        ViewPager viewPager;
        ViewPagerAdapter viewPagerAdapter;


        public StudentrFragment() {
            // Required empty public constructor
        }


        @Override
        public void onCreate(Bundle savedInstanceState){
            super.onCreate(savedInstanceState);
            setContentView(R.layout.tabbar_layout);
            toolbar = (Toolbar) findViewById(R.id.toolbar);
            setSupportActionBar(toolbar); 
            tabLayout = (TabLayout) findViewById(R.id.tabLayout);
            viewPager = (ViewPager) findViewById(R.id.viewPager);
            viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
            viewPagerAdapter.addFragments(new CivilFragment(),"Civil Dept");
            viewPagerAdapter.addFragments(new ComputerFragment(),"CSE Dept");
            viewPagerAdapter.addFragments(new EeeFragment(),"EEE Dept");
            viewPagerAdapter.addFragments(new EceFragment(),"ECE Dept");
            viewPager.setAdapter(viewPagerAdapter);
            tabLayout.setupWithViewPager(viewPager);

        }

    }

Answer 1

你可以在片段中这样设置SupportActionbar：

((AppCompatActivity)getActivity()).setSupportActionBar(mToolbar);

您需要在onCreateView 的Fragment 中膨胀tabbar_layout。 像这样：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.tabbar_layout, container, false);
 //YOUR STUFF
return rootView;
}

Answer 2

suggested solution 可以工作，但它看起来并不优雅，理想情况下，片段不应该对其父活动一无所知。另一种方法可能是根本不使用setSupportActionBar。如果您使用navigation 库，则可能更容易将Toolbar 添加到片段布局并使用NavigationUI 进行设置，例如：

<!-- my_fragment.xml -->
<androidx.constraintlayout.widget.ConstraintLayout ... >

  <com.google.android.material.appbar.MaterialToolbar
    android:id="@+id/toolbar"
    app:menu="@menu/my_fragment_menu"
    ... />

</androidx.constraintlayout.widget.ConstraintLayout>

class MyFragment : Fragment() {
  ...

  override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    val navController = findNavController()
    binding.toolbar.setupWithNavController(navController)

    binding.toolbar.setOnMenuItemClickListener {
      when (it.itemId) {
        // these ids should match the item ids from my_fragment_menu.xml file
        R.id.edit -> {
          Log.i("MyFragment", "edit menu item is clicked")

          // by returning 'true' we're saying that the event 
          // is handled and it shouldn't be propagated further
          true
        }
        else -> false
      }
    }

    // if you prefer not to use xml menu file 
    // you can also add menu items programmatically
    val shareMenuItem = binding.toolbar.menu.add(R.string.share)
    shareMenuItem.setOnMenuItemClickListener {
      Log.i("MyFragment", "share menu item is clicked")
      true
    }
  }
}

您可以找到完整的 GitHub 示例 here。另请查看另一个问题Is setSupportActionbar required anymore? 和我的answer 了解更多详情。

Answer 3

This site has the solution which worked for me!

粘贴它：

toolbar = (Toolbar) getView().findViewById(R.id.toolbar);

AppCompatActivity activity = (AppCompatActivity) getActivity();

activity.setSupportActionBar(toolbar);

Answer 4

在 Kotlin 中为导航菜单设置支持操作栏：

(activity as AppCompatActivity?)!!.setSupportActionBar(customToolbar as Toolbar?)

还可以在 DrawerLayout 切换时为汉堡包图标设置动画：

val actionBarDrawerToggle: ActionBarDrawerToggle = object : ActionBarDrawerToggle(activity,
                drawer_layout, customToolbar as Toolbar?, R.string.open_drawer, R.string.close_drawer) { }
    
drawer_layout.addDrawerListener(actionBarDrawerToggle)
actionBarDrawerToggle.syncState()