安卓:在底部导航视图的菜单之间切换时出现问题

Question

我正在为我的应用程序使用底部导航视图。在这里，我在菜单中添加了3个项目，并自定义了底部导航视图的app：itemTextAppearanceActive &app：itemTextAppearanceInactive属性，如下所示：

<android.support.constraint.ConstraintLayout
android:layout_below="@+id/tb_home"
android:id="@+id/cl_home_stats"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
<android.support.design.widget.BottomNavigationView
android:id="@+id/bnv_home_stats"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="?android:attr/windowBackground"
android:soundEffectsEnabled="true"
app:labelVisibilityMode="labeled"
app:itemTextAppearanceActive="@style/navTextActive"
app:itemTextAppearanceInactive="@style/navTextInactive"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:menu="@menu/navigation"/>
</android.support.constraint.ConstraintLayout>

在样式 XML 文件中：

<style name="navTextInactive">
<item name="android:textSize">20dp</item>
<item name="android:textColor">@color/colorInActive</item>
</style>
<style name="navTextActive">
<item name="android:textSize">20dp</item>
<item name="android:textStyle">bold</item>
<item name="android:textColor">@color/colorActive</item>
</style>

单击导航菜单时，其他菜单的活动和非活动状态没有变化。即使您选择其他菜单，第一个菜单仍保留活动选择。

活动视图的完整 xml 文件：

<?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=".HomeActivity"
tools:showIn="@layout/app_bar_home">
<RelativeLayout
android:id="@+id/rl_home"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="visible">
<android.support.design.widget.TabLayout
android:id="@+id/tb_home"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabTextAppearance="@style/MyCustomTabText"
android:visibility="gone">
<android.support.design.widget.TabItem
android:id="@+id/tb_home_billing"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/title_billing"/>
<android.support.design.widget.TabItem
android:id="@+id/tb_home_stats"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/title_stats" />
</android.support.design.widget.TabLayout>
<RelativeLayout
android:layout_below="@+id/tb_home"
android:id="@+id/rl_home_billing"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone">
<Button
android:id="@+id/bt_home_billing_order"
android:layout_alignParentStart="true"
android:layout_width="160dp"
android:layout_height="80dp"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:text="@string/title_order"
android:textSize="20sp"
android:textStyle="bold"/>
<Button
android:id="@+id/bt_home_billing_parcel"
android:layout_alignParentEnd="true"
android:layout_width="160dp"
android:layout_height="80dp"
android:layout_marginTop="10dp"
android:layout_marginEnd="10dp"
android:text="@string/title_parcel"
android:textSize="20sp"
android:textStyle="bold"/>
<ExpandableListView
android:id="@+id/elv_home_billing_unsettled"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/bt_home_billing_order"
android:layout_marginTop="30dp"
android:layout_marginStart="10dp"
android:layout_marginEnd="10dp"
android:indicatorLeft="?android:attr/expandableListPreferredItemIndicatorLeft"
android:divider="@android:color/darker_gray"
android:dividerHeight="0.5dp">
</ExpandableListView>
</RelativeLayout>
<android.support.constraint.ConstraintLayout
android:layout_below="@+id/tb_home"
android:id="@+id/cl_home_stats"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
<android.support.design.widget.BottomNavigationView
android:id="@+id/bnv_home_stats"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="?android:attr/windowBackground"
android:soundEffectsEnabled="true"
app:labelVisibilityMode="labeled"
app:itemTextAppearanceActive="@style/navTextActive"
app:itemTextAppearanceInactive="@style/navTextInactive"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:menu="@menu/navigation"/>
</android.support.constraint.ConstraintLayout>
</RelativeLayout>
</android.support.constraint.ConstraintLayout>

Answer 1

首先在主布局中添加以下代码：

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="?attr/actionBarSize">
<com.google.android.material.tabs.TabLayout
android:layout_width="match_parent"
android:layout_height="40dp"
tools:ignore="MissingConstraints" >
</com.google.android.material.tabs.TabLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="0dp"
android:layout_marginEnd="0dp"
android:background="?android:attr/windowBackground"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="@menu/bottom_nav_menu" />
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_constraintBottom_toTopOf="@id/nav_view"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="@navigation/mobile_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>

在名为bottom_nav_menu.xml的菜单中：

<item
android:id="@+id/navigation_home"
android:icon="@drawable/ic_home_black_24dp"
android:title="@string/title_home" />
<item
android:id="@+id/navigation_dashboard"
android:icon="@drawable/ic_dashboard_black_24dp"
android:title="@string/title_dashboard" />
<item
android:id="@+id/navigation_notifications"
android:icon="@drawable/ic_notifications_black_24dp"
android:title="@string/title_notifications" />

以及要切换的片段，您应该添加这些fragment.

对于活动代码是：

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BottomNavigationView navView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
AppBarConfiguration appBarConfiguration = new AppBarConfiguration.Builder(
R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications)
.build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
NavigationUI.setupWithNavController(navView, navController);
}

从Android-Studio您可以自动启动此操作：

新项目>手机和平板电脑>导航抽屉活动>完成

或对于新activity：

新>活动>底部导航活动>完成。

希望它能对您有所帮助，否则您可以问我评论。 谢谢。