Question

工具栏菜单被部分放大，然后稍后清除。

第一次创建（或旋转）活动时，工具栏菜单会在片段中正确放大，但随后会清除，然后才能显示。

我在片段的onActivityCreated中设置了工具栏菜单，并且在活动中一直通过onResume进行设置。我发现的下一个通话是在活动中的onCreateOptionsMenu中，但此时toolbar.getMenu().size() = 0

工具栏菜单在onResume和onCreateOptionsMenu之间的某个位置被重置。

编辑：我不确定要重现它是什么，但是这里是所有相关代码。活动：

    private Toolbar toolbar;
    private DrawerLayout drawer;
    private ActionBarDrawerToggle toggle;
    private FloatingActionButton fab;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.drawer_main);
        toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        fab = findViewById(R.id.main_fab);
        drawer = findViewById(R.id.drawer_layout);
        toggle = new ActionBarDrawerToggle(this, drawer,toolbar,R.string.nav_drawer_open,R.string.nav_drawer_close);
        drawer.addDrawerListener(toggle);
        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
        if (savedInstanceState == null) {
            showFragment(ScheduleFragment.newInstance());
        }
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(toggle.onOptionsItemSelected(item)) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        CharSequence retainTitle = toolbar.getTitle();
        super.onPostCreate(savedInstanceState);
        toggle.syncState();
        toolbar.setTitle(retainTitle);
    }

片段：

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        toolbar = ((MainActivity)getActivity()).getToolbar();
        setMenuAction(MENU_ACTION_DELETE);
    }
    protected void setMenuAction(int menuAction) {
        Log.d(logger, "setting the menu");
        switch(menuAction) {
            case MENU_ACTION_DELETE:
                toolbar.getMenu().clear();
                toolbar.inflateMenu(R.menu.menu_delete);
                break;
            case MENU_ACTION_NONE:
                Log.d(logger, "clearing menu");
                toolbar.getMenu().clear();
                break;
        }
    }

布局：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout">
    <include
        layout="@layout/activity_main"/>
    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/menu_nav" />

</android.support.v4.widget.DrawerLayout>

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|snap|enterAlways"
            app:popupTheme="@style/AppTheme.PopupOverlay" />
    </android.support.design.widget.AppBarLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/main_fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:src="@drawable/ic_baseline_add_24px"
        android:layout_margin="16dp" />

    <include layout="@layout/content_main"/>
</android.support.design.widget.CoordinatorLayout>

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".MainActivity"
    tools:showIn="@layout/activity_main">

    <FrameLayout
        android:id="@+id/fragmentHolder"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

Answer 1

我当前发布的代码中的问题是行setSupportActionBar(toolbar);

这不是必需的，实际上导致了上述令人困扰的生命周期问题。

设置后清除工具栏菜单（开始活动时）

1 个答案: