在底部导航片段之间切换时工具栏会闪烁

Question

\xe3\x80\x90update\xe3\x80\x91\n实际上，只需禁用默认的 ActionBar 并为每个片段添加工具栏即可轻松重现该问题。然后您可以看到切换底部目标时工具栏会闪烁。\n\n请查看https://github.com/025nju/BottomNav上的小演示

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\xe3\x80\x90原始帖子\xe3\x80\x91\n我是 Android 新手，我的演示项目是 BottomNav 单活动项目。我检查了很多帖子，看起来很多人都在这种情况下处理工具栏，所有片段都需要有自己的工具栏。

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在底部选项卡之间切换时，工具栏背景颜色会闪烁。请查看 gif 并忽略最后一个空白帧。\n

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如何消除闪烁？\nbtw，当我使用默认的ActionBar时没有出现这样的问题，这是官方不推荐的。\n我在Nexus 6 api26 AVD和真机android版本9上进行了测试。同样的问题。下面是相关代码供大家参考。多谢。

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FragmentMoney.xml：

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<?xml version="1.0" encoding="utf-8"?>\n<layout xmlns:android="http://schemas.android.com/apk/res/android"\n    xmlns:app="http://schemas.android.com/apk/res-auto"\n    xmlns:tools="http://schemas.android.com/tools">\n<data>\n</data>\n<androidx.constraintlayout.widget.ConstraintLayout\n    android:layout_width="match_parent"\n    android:layout_height="match_parent"\n    tools:context=".ui.money.MoneyFragment">\n\n    <include android:id="@+id/fragment_base" layout="@layout/fragment_base"/>\n\n    <TextView\n        android:id="@+id/text_money"\n        ... />\n</androidx.constraintlayout.widget.ConstraintLayout>\n

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fragment_base.xml 用于工具栏定义：

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<?xml version="1.0" encoding="utf-8"?>\n<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"\n    xmlns:app="http://schemas.android.com/apk/res-auto"\n    android:layout_width="match_parent"\n    android:layout_height="match_parent">\n<com.google.android.material.appbar.AppBarLayout\n    android:layout_width="match_parent"\n    android:layout_height="wrap_content">\n\n    <com.google.android.material.appbar.MaterialToolbar\n        android:id="@+id/mToolbar"\n        android:layout_width="match_parent"\n        android:layout_height="?attr/actionBarSize"\n        android:background="?attr/colorPrimary"\n        android:elevation="4dp"\n        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"\n        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"\n        app:layout_constraintTop_toTopOf="parent">\n    </com.google.android.material.appbar.MaterialToolbar>\n\n</com.google.android.material.appbar.AppBarLayout>\n\n</androidx.coordinatorlayout.widget.CoordinatorLayout>\n

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MoneyFragment.java：

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public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {\n    View root = fragmentMoneyBinding.getRoot();\n    ...\n    Toolbar mToolbar = (Toolbar) root.findViewById(R.id.mToolbar);\n    mToolbar.setTitle(R.string.title_money);\n    ((AppCompatActivity) getActivity()).setSupportActionBar(mToolbar);\n    return root;\n    }\n}\n

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活动_main.xml：

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<?xml version="1.0" encoding="utf-8"?>\n<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"\nxmlns:app="http://schemas.android.com/apk/res-auto"\nxmlns:tools="http://schemas.android.com/tools"\nandroid:id="@+id/container"\nandroid:layout_width="match_parent"\nandroid:layout_height="match_parent">\n\n<fragment\n    android:id="@+id/nav_host_fragment"\n    android:name="androidx.navigation.fragment.NavHostFragment"\n    android:layout_width="match_parent"\n    android:layout_height="0dp"\n    app:defaultNavHost="true"\n    app:layout_constraintBottom_toTopOf="@+id/nav_view"\n    app:layout_constraintEnd_toEndOf="parent"\n    app:layout_constraintStart_toStartOf="parent"\n    app:layout_constraintTop_toTopOf="parent"\n    app:navGraph="@navigation/mobile_navigation" />\n\n<com.google.android.material.bottomnavigation.BottomNavigationView\n    android:id="@+id/nav_view"\n    android:layout_width="0dp"\n    android:layout_height="wrap_content"\n    android:layout_marginStart="0dp"\n    android:layout_marginEnd="0dp"\n    android:background="?android:attr/windowBackground"\n    app:layout_constraintBottom_toBottomOf="parent"\n    app:layout_constraintTop_toBottomOf="@id/nav_host_fragment"\n    app:layout_constraintLeft_toLeftOf="parent"\n    app:layout_constraintRight_toRightOf="parent"\n    app:menu="@menu/bottom_nav_menu" />\n\n<com.google.android.material.floatingactionbutton.FloatingActionButton\n    android:id="@+id/floatingActionButton"\n    ... />\n\n</androidx.constraintlayout.widget.ConstraintLayout>\n

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MainActivity.java：

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@Override\nprotected void onCreate(Bundle savedInstanceState) {\n    super.onCreate(savedInstanceState);\n    setContentView(R.layout.activity_main);\n    BottomNavigationView navView = findViewById(R.id.nav_view);\n    appBarConfiguration = new AppBarConfiguration.Builder(\n            R.id.navigation_note, R.id.navigation_money, R.id.navigation_time)\n            .build();\n    navController = Navigation.findNavController(this, R.id.nav_host_fragment);\n    NavigationUI.setupWithNavController(navView, navController);\n}\n...\n}\n

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Answer 1

您必须禁用（替换）片段之间的动画。

创建空动画：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <!--Empty to disable animation-->
</set>

并将其放入以下文件中：

res/animator/nav_default_enter_anim.xml
res/animator/nav_default_exit_anim.xml
res/animator/nav_default_pop_enter_anim.xml
res/animator/nav_default_pop_exit_anim.xml