android - 如何将工具栏添加到android中的 fragment ？

Question

我有一个名为 HomeFragment.java 的 fragment ，它扩展了 Fragment 类。

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.android.test.R;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;

public class HomeFragment extends Fragment {

    private Toolbar toolbar;
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_profile,container,false);
        toolbar = (Toolbar) view.findViewById(R.id.toolbar);
        getActivity().setSupportActionController(toolbar);
        //setSupportActionBar(toolbar);
        return view;
    }
}

但是我在行中遇到了错误:

getActivity().setSupportActionController(toolbar)

错误是:

Cannot resolve method 'setSupportActionController(android.support.v7.widget.Toolbar)'

而且有一个条件，我不能将我的HomeFragment 扩展到AppCombatActivity。它必须仅保留为 Fragment，即 public class HomeFragment extends Fragment。

条件是因为这段代码中的第5行

    Runnable mPendingRunnable = new Runnable() {
        @Override
        public void run() {
            // update the main content by replacing fragments
            Fragment fragment = getHomeFragment();
            FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
            fragmentTransaction.setCustomAnimations(android.R.anim.fade_in,
                    android.R.anim.fade_out);
            fragmentTransaction.replace(R.id.frame, fragment, CURRENT_TAG);
            fragmentTransaction.commitAllowingStateLoss();
        }
    };

    // If mPendingRunnable is not null, then add to the message queue
    if (mPendingRunnable != null) {
        mHandler.post(mPendingRunnable);
    }

    // show or hide the fab button
    toggleFab();

    //Closing drawer on item click
    drawer.closeDrawers();

    // refresh toolbar menu
    invalidateOptionsMenu();
}

我的 getHomeFragment() 是:

    private Fragment getHomeFragment() {
    switch (navItemIndex) {
        case 0:
            // home
            HomeFragment homeFragment = new HomeFragment();
            return homeFragment;
        case 1:
            // photos
            PhotosFragment photosFragment = new PhotosFragment();
            return photosFragment;
        case 2:
            // movies fragment
            MoviesFragment moviesFragment = new MoviesFragment();
            return moviesFragment;
        case 3:
            // notifications fragment
            NotificationsFragment notificationsFragment = new NotificationsFragment();
            return notificationsFragment;

        case 4:
            // settings fragment
            SettingsFragment settingsFragment = new SettingsFragment();
            return settingsFragment;
        default:
            return new HomeFragment();
    }
}

所以如果我将public class HomeFragment extends Fragment更改为public class HomeFragment extends AppCombatActivity，上面代码中的返回语句将给出不兼容类型错误 .

请帮助我解决这个错误，因为这个错误我无法创建工具栏或操作栏。任何帮助将不胜感激。谢谢!

Answer 1

首先将您的 Activity 从 getActivity() 转换为 AppCompatActivity。我认为这将解决您的错误:

((AppCompatActivity) getActivity()).getSupportActionBar(toolbar);

或者在你的情况下:

((AppCompatActivity) getActivity()).setSupportActionController(toolbar);

getActivity() 返回一个 FragmentActivity，您需要返回 AppCompatActivity。希望这对您有所帮助!