汉堡图标在导航抽屉片段中未显示

Question

我正在使用一个片段来创建导航抽屉，因此无法使用onPostCreated调用syncState。

public class NavigationDrawerFragment extends Fragment{
....

在 activityCreated 中调用 syncState()

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    // Indicate that this fragment would like to influence the set of actions in the action bar.
    setHasOptionsMenu(true);
    mDrawerToggle.syncState();
}

使用ic_drawer来代替图标。

public void setUp(int fragmentId, DrawerLayout drawerLayout) {
    mFragmentContainerView = getActivity().findViewById(fragmentId);
    mDrawerLayout = drawerLayout;

    // set a custom shadow that overlays the main content when the drawer opens
    mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
    // set up the drawer's list view with items and click listener

    ActionBar actionBar = getActionBar();
    actionBar.setDisplayHomeAsUpEnabled(true);
    actionBar.setHomeButtonEnabled(true);

    // ActionBarDrawerToggle ties together the the proper interactions
    // between the navigation drawer and the action bar app icon.
    mDrawerToggle = new ActionBarDrawerToggle(
            getActivity(),                    /* host Activity */
            mDrawerLayout,                    /* DrawerLayout object */
            R.drawable.ic_drawer,             /* nav drawer image to replace 'Up' caret */
            R.string.navigation_drawer_open,  /* "open drawer" description for accessibility */
            R.string.navigation_drawer_close  /* "close drawer" description for accessibility */
    ) {
        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            if (!isAdded()) {
                return;
            }

            getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
        }

        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            if (!isAdded()) {
                return;
            }

            if (!mUserLearnedDrawer) {
                // The user manually opened the drawer; store this flag to prevent auto-showing
                // the navigation drawer automatically in the future.
                mUserLearnedDrawer = true;
                SharedPreferences sp = PreferenceManager
                        .getDefaultSharedPreferences(getActivity());
                sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
            }

            getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
        }


    };

无法确定问题出在哪里。 请帮忙！

- viki

Answer 1

我也遇到过这个问题。对于我来说，使用 android.support.v7.app.ActionBarDrawerToggle 替代 android.support.v4.app.ActionBarDrawerToggle 可以解决此问题。您还需要在定义 mDrawerToggle 时删除 R.drawable.ic_drawer 参数：

mDrawerToggle = new ActionBarDrawerToggle( getActivity(), mDrawerLayout, R.string.navigation_drawer_open, R.string.navigation_drawer_close )

如果这不起作用，请尝试一些回答此问题的答案：这个问题。

- MaximusJohnsonus

---

我正在使用android.support.v7.app.ActionBarDrawerToggle，但是没有运气，有什么想法吗？ - Suchith

@Suchith，我曾遇到相同的问题，是因为我覆盖了错误的public void onPostCreate（Bundle savedInstanceState，PersistableBundle persistentState）方法，它应该是protected void onPostCreate（Bundle savedInstanceState）。 - aglour

尽管我的代码和逻辑与问题非常相似，但这对我不起作用。但是我有这行代码的区别： mActionBarDrawerToggle = new ActionBarDrawerToggle(getActivity(), mDrawerLayout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_item_close) - blueware

Answer 2

对我来说，被接受的答案没有解决我的问题，后来我发现我的 onPostCreate 覆盖方法是错误的。

@Override
public void onPostCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
    super.onPostCreate(savedInstanceState, persistentState);
    mDrawerToggle.syncState();
}

必须是这样

@Override
public void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    mDrawerToggle.syncState();
}

- aglour