Question

我正在使用导航抽屉，最近我更改了build.gradle以使用API 23编译应用程序。我注意到onAttach的方法已被弃用。我在这个论坛找到了几个解决方案，Android Fragment onAttach() deprecated但是没有一个解决方案，你有其他解决方案吗？谢谢

   public class NavigationDrawerFragment extends Fragment implements NavigationDrawerCallbacks {
 private NavigationDrawerCallbacks mCallbacks;
    private RecyclerView mDrawerList;
    private View mFragmentContainerView;
    private DrawerLayout mDrawerLayout;
    private ActionBarDrawerToggle mActionBarDrawerToggle;
    private boolean mUserLearnedDrawer;
    private boolean mFromSavedInstanceState;
    private int mCurrentSelectedPosition;
 @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
mDrawerList = (RecyclerView) view.findViewById(R.id.drawerList);
        LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        mDrawerList.setLayoutManager(layoutManager);
        mDrawerList.setHasFixedSize(true);

        final List<NavigationItem> navigationItems = getMenu();
        NavigationDrawerAdapter adapter = new NavigationDrawerAdapter(navigationItems);
        adapter.setNavigationDrawerCallbacks(this);
        mDrawerList.setAdapter(adapter);
        selectItem(mCurrentSelectedPosition);


        return view;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mUserLearnedDrawer = Boolean.valueOf(readSharedSetting(getActivity(), PREF_USER_LEARNED_DRAWER, "false"));
        if (savedInstanceState != null) {
            mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
            mFromSavedInstanceState = true;
        }
    }


    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mCallbacks = (NavigationDrawerCallbacks) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
        }
    }

    public ActionBarDrawerToggle getActionBarDrawerToggle() {
        return mActionBarDrawerToggle;
    }

    public void setActionBarDrawerToggle(ActionBarDrawerToggle actionBarDrawerToggle) {
        mActionBarDrawerToggle = actionBarDrawerToggle;
    }

    public void setup(int fragmentId, DrawerLayout drawerLayout, Toolbar toolbar) {
        mFragmentContainerView = getActivity().findViewById(fragmentId);
        mDrawerLayout = drawerLayout;
        mActionBarDrawerToggle = new ActionBarDrawerToggle(getActivity(), mDrawerLayout, toolbar, R.string.app_name, R.string.app_name) {
            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                if (!isAdded()) return;
                getActivity().invalidateOptionsMenu();
            }

            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                if (!isAdded()) return;
                if (!mUserLearnedDrawer) {
                    mUserLearnedDrawer = true;
                    saveSharedSetting(getActivity(), PREF_USER_LEARNED_DRAWER, "true");
                }

                getActivity().invalidateOptionsMenu();
            }
        };

        if (!mUserLearnedDrawer && !mFromSavedInstanceState)
            mDrawerLayout.openDrawer(mFragmentContainerView);

        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mActionBarDrawerToggle.syncState();
            }
        });

        mDrawerLayout.setDrawerListener(mActionBarDrawerToggle);
    }

    public void openDrawer() {
        mDrawerLayout.openDrawer(mFragmentContainerView);
    }

    public void closeDrawer() {
        mDrawerLayout.closeDrawer(mFragmentContainerView);
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mCallbacks = null;
    }

    public List<NavigationItem> getMenu() {
        List<NavigationItem> items = new ArrayList<NavigationItem>();
        items.add(new NavigationItem(getString(R.string.nav1), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_home_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav2), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_content_paste_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav3), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_format_list_bulleted_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav4), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_receipt_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav5), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_trending_down_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav6), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_donut_large_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav7), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_equalizer_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav8), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_search_black_24dp, null)));
        items.add(new NavigationItem(getString(R.string.nav9), ResourcesCompat.getDrawable(getResources(), R.mipmap.ic_settings_black_24dp, null)));

        return items;
    }

    void selectItem(int position) {
        mCurrentSelectedPosition = position;
        if (mDrawerLayout != null) {
            mDrawerLayout.closeDrawer(mFragmentContainerView);
        }
        if (mCallbacks != null) {
            mCallbacks.onNavigationDrawerItemSelected(position);
        }
        ((NavigationDrawerAdapter) mDrawerList.getAdapter()).selectPosition(position);
    }

    public boolean isDrawerOpen() {
        return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        mActionBarDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {
        selectItem(position);
    }

    public DrawerLayout getDrawerLayout() {
        return mDrawerLayout;
    }

    public void setDrawerLayout(DrawerLayout drawerLayout) {
        mDrawerLayout = drawerLayout;
    }

    public static void saveSharedSetting(Context ctx, String settingName, String settingValue) {
        SharedPreferences sharedPref = ctx.getSharedPreferences(PREFERENCES_FILE, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPref.edit();
        editor.putString(settingName, settingValue);
        editor.apply();
    }

    public static String readSharedSetting(Context ctx, String settingName, String defaultValue) {
        SharedPreferences sharedPref = ctx.getSharedPreferences(PREFERENCES_FILE, Context.MODE_PRIVATE);
        return sharedPref.getString(settingName, defaultValue);
    }

Answer 1

不确定您找到的解决方案有什么问题。但onAttach应该接受一个上下文。活动是一个上下文，因此以下内容应该有效。

@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
    mCallbacks = (NavigationDrawerCallbacks) context;
} catch (ClassCastException e) {
    throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
}

}

Android NavigationDrawer onAttach已弃用

1 个答案: