为什么我的应用程序在更改 AppTheme 时崩溃
Why do my App crashes when the AppTheme is changed
将 AppTheme 从 <style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar"> 更改为 <style name="AppTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">
后，我的应用程序在启动时崩溃
以下是'HomeActivity.kt'
class HomeActivity : BaseActivity() {
private lateinit var binding: ActivityHomeBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
supportActionBar
binding = ActivityHomeBinding.inflate(layoutInflater)
setContentView(binding.root)
val window = window
window.statusBarColor = R.drawable.app_gradient_color_background
binding.navView.background = null
supportActionBar!!.setBackgroundDrawable(
ContextCompat.getDrawable(
this@HomeActivity,
R.drawable.app_gradient_color_background
)
)
val navView: BottomNavigationView = findViewById(R.id.nav_view)
val navController = findNavController(R.id.nav_host_fragment)
val appBarConfiguration = AppBarConfiguration(
setOf(
R.id.nav_home,
R.id.nav_orders,
R.id.nav_cart
)
)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
override fun onBackPressed() {
doubleBackToExit()
}
}
以下是'Logcat'
2021-11-23 02:04:20.714 11275-11275/com.abc.xyz E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.abc.xyz, PID: 11275
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: java.lang.NullPointerException
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:47)
at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
请帮我解决这个错误。
修复：
我在 xml 布局文件中添加了以下内容
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="24dp"/>
以及 'HomeActivity.kt' 的 onCreate 中的以下内容
setSupportActionBar(binding.toolbarHome)
但是最后的结果并不如我所料
1- 我在顶部看不到工具栏
2- BottomNavigationView 的颜色在 Dark mode 为 'ON' 时变为深色，我不希望这种情况发生。我想要它的颜色永远是白色。
以下是'activity_home.xml'
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="24dp""/>
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:fabCradleMargin="10dp"
app:fabCradleRoundedCornerRadius="50dp">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:itemIconTint="@color/bottom_nav_color"
app:itemTextColor="@color/bottom_nav_color"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab_new"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="Show Categories"
android:scaleType="center"
app:layout_anchor="@id/bottom_appbar"
app:maxImageSize="56dp"
app:srcCompat="@drawable/fab_image"
app:tint="@null" />
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="50dp"
app:defaultNavHost="true"
app:layout_anchor="@id/bottom_appbar"
app:navGraph="@navigation/mobile_navigation" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
以下是我在创建自己的工具栏之前在“HomeFragment.kt”中的内容。如何让我的新工具栏在 'HomeFragment'?
中可用
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.home, menu)
super.onCreateOptionsMenu(menu, inflater)
编辑：
注意：我刚刚注意到有关菜单图标颜色的问题，'Dark Mode' 开启时图标为白色，关闭时图标为黑色。我希望它永远是白色的。
当我将 fragment 更改为 androidx.fragment.app.FragmentContainerView 时，应用程序崩溃并出现以下错误。错误 com.abc.xyz.ui.activities.HomeActivity.onCreateHomeActivity.kt:62) 指向 val navController = findNavController(R.id.nav_host_fragment)
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: java.lang.IllegalStateException: Activity com.abc.xyz.ui.activities.HomeActivity@2ed3cdc does not have a NavController set on 2131296976
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: java.lang.IllegalStateException: Activity com.abc.xyz.ui.activities.HomeActivity@2ed3cdc does not have a NavController set on 2131296976
at androidx.navigation.Navigation.findNavController(Navigation.java:61)
at androidx.navigation.ActivityKt.findNavController(Activity.kt:30)
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:62)
at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3808)
我添加了 app:titleTextColor="@color/colorWhite" 来更改标题的颜色，因为当我添加新的自定义工具栏时，它已更改为黑色。但是，我无法更改 toolbar 中菜单项（搜索、设置）和溢出图标的颜色。正如您在下面的两张图片中看到的那样，它是白色的，而当我 运行 应用程序时它们是黑色的。你能告诉我应该在哪里进行更改吗？
'home_menu.xml'
@drawable/ic_search
因此，通过添加自定义工具栏作为 supportActionBar
解决了原始问题
1- I can't see a toolbar at the top
因为它被 fragment 遮挡了（即它在它后面），要解决此问题，请将工具栏和片段添加到 ConstraintLayout 中并调整约束以使它们不重叠：
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:fabCradleMargin="10dp"
app:fabCradleRoundedCornerRadius="50dp">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:itemIconTint="@color/bottom_nav_color"
app:itemTextColor="@color/bottom_nav_color"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab_new"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="Show Categories"
android:scaleType="center"
app:layout_anchor="@id/bottom_appbar"
app:maxImageSize="56dp"
app:srcCompat="@drawable/fab_image"
app:tint="@null" />
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<androidx.fragment.app.FragmentContainerView
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="@+id/toolbar_home"
android:layout_marginBottom="50dp"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
app:navGraph="@navigation/mobile_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
也不需要工具栏的上边距，所以android:layout_marginTop="24dp"被移除了。
这个app:layout_anchor="@id/bottom_appbar"需要从fragment中删除，它只需要在fab中锚定到底部栏。
将 fragment 更改为 androidx.fragment.app.FragmentContainerView，因为此处的 fragment 已弃用。
2- The colour of the BottomNavigationView is changed to dark when the Dark mode is 'ON', I don't want that to happen. I want the colour
of it white always.
如果你有 themes.xml 文件的夜间版本；请删除它；如果没有固定；请分享此文件
将 AppTheme 从 <style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar"> 更改为 <style name="AppTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">
以下是'HomeActivity.kt'
class HomeActivity : BaseActivity() {
private lateinit var binding: ActivityHomeBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
supportActionBar
binding = ActivityHomeBinding.inflate(layoutInflater)
setContentView(binding.root)
val window = window
window.statusBarColor = R.drawable.app_gradient_color_background
binding.navView.background = null
supportActionBar!!.setBackgroundDrawable(
ContextCompat.getDrawable(
this@HomeActivity,
R.drawable.app_gradient_color_background
)
)
val navView: BottomNavigationView = findViewById(R.id.nav_view)
val navController = findNavController(R.id.nav_host_fragment)
val appBarConfiguration = AppBarConfiguration(
setOf(
R.id.nav_home,
R.id.nav_orders,
R.id.nav_cart
)
)
setupActionBarWithNavController(navController, appBarConfiguration)
navView.setupWithNavController(navController)
}
override fun onBackPressed() {
doubleBackToExit()
}
}
以下是'Logcat'
2021-11-23 02:04:20.714 11275-11275/com.abc.xyz E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.abc.xyz, PID: 11275
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: java.lang.NullPointerException
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:47)
at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
请帮我解决这个错误。
修复：
我在 xml 布局文件中添加了以下内容
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="24dp"/>
以及 'HomeActivity.kt' 的 onCreate 中的以下内容
setSupportActionBar(binding.toolbarHome)
但是最后的结果并不如我所料
1- 我在顶部看不到工具栏
2- BottomNavigationView 的颜色在 Dark mode 为 'ON' 时变为深色，我不希望这种情况发生。我想要它的颜色永远是白色。
以下是'activity_home.xml'
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="24dp""/>
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:fabCradleMargin="10dp"
app:fabCradleRoundedCornerRadius="50dp">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:itemIconTint="@color/bottom_nav_color"
app:itemTextColor="@color/bottom_nav_color"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab_new"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="Show Categories"
android:scaleType="center"
app:layout_anchor="@id/bottom_appbar"
app:maxImageSize="56dp"
app:srcCompat="@drawable/fab_image"
app:tint="@null" />
<fragment
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="50dp"
app:defaultNavHost="true"
app:layout_anchor="@id/bottom_appbar"
app:navGraph="@navigation/mobile_navigation" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
以下是我在创建自己的工具栏之前在“HomeFragment.kt”中的内容。如何让我的新工具栏在 'HomeFragment'?
中可用 override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.home, menu)
super.onCreateOptionsMenu(menu, inflater)
编辑：
注意：我刚刚注意到有关菜单图标颜色的问题，'Dark Mode' 开启时图标为白色，关闭时图标为黑色。我希望它永远是白色的。
当我将 fragment 更改为 androidx.fragment.app.FragmentContainerView 时，应用程序崩溃并出现以下错误。错误 com.abc.xyz.ui.activities.HomeActivity.onCreateHomeActivity.kt:62) 指向 val navController = findNavController(R.id.nav_host_fragment)
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.abc.xyz/com.abc.xyz.ui.activities.HomeActivity}: java.lang.IllegalStateException: Activity com.abc.xyz.ui.activities.HomeActivity@2ed3cdc does not have a NavController set on 2131296976
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3835)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4011)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2325)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:246)
at android.app.ActivityThread.main(ActivityThread.java:8633)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:602)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1130)
Caused by: java.lang.IllegalStateException: Activity com.abc.xyz.ui.activities.HomeActivity@2ed3cdc does not have a NavController set on 2131296976
at androidx.navigation.Navigation.findNavController(Navigation.java:61)
at androidx.navigation.ActivityKt.findNavController(Activity.kt:30)
at com.abc.xyz.ui.activities.HomeActivity.onCreate(HomeActivity.kt:62)
at android.app.Activity.performCreate(Activity.java:8207)
at android.app.Activity.performCreate(Activity.java:8191)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3808)
我添加了 app:titleTextColor="@color/colorWhite" 来更改标题的颜色，因为当我添加新的自定义工具栏时，它已更改为黑色。但是，我无法更改 toolbar 中菜单项（搜索、设置）和溢出图标的颜色。正如您在下面的两张图片中看到的那样，它是白色的，而当我 运行 应用程序时它们是黑色的。你能告诉我应该在哪里进行更改吗？
'home_menu.xml'
@drawable/ic_search
因此，通过添加自定义工具栏作为 supportActionBar
1- I can't see a toolbar at the top
因为它被 fragment 遮挡了（即它在它后面），要解决此问题，请将工具栏和片段添加到 ConstraintLayout 中并调整约束以使它们不重叠：
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.bottomappbar.BottomAppBar
android:id="@+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:fabCradleMargin="10dp"
app:fabCradleRoundedCornerRadius="50dp">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/nav_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginEnd="16dp"
android:background="@android:color/transparent"
app:itemIconTint="@color/bottom_nav_color"
app:itemTextColor="@color/bottom_nav_color"
app:menu="@menu/bottom_nav_menu" />
</com.google.android.material.bottomappbar.BottomAppBar>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab_new"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="Show Categories"
android:scaleType="center"
app:layout_anchor="@id/bottom_appbar"
app:maxImageSize="56dp"
app:srcCompat="@drawable/fab_image"
app:tint="@null" />
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_home"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@drawable/app_gradient_color_background"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<androidx.fragment.app.FragmentContainerView
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="@+id/toolbar_home"
android:layout_marginBottom="50dp"
app:layout_constraintBottom_toBottomOf="parent"
app:defaultNavHost="true"
app:navGraph="@navigation/mobile_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
也不需要工具栏的上边距，所以
android:layout_marginTop="24dp"被移除了。这个
app:layout_anchor="@id/bottom_appbar"需要从fragment中删除，它只需要在fab中锚定到底部栏。将
fragment更改为androidx.fragment.app.FragmentContainerView，因为此处的fragment已弃用。
2- The colour of the BottomNavigationView is changed to dark when the Dark mode is 'ON', I don't want that to happen. I want the colour of it white always.
如果你有 themes.xml 文件的夜间版本；请删除它；如果没有固定；请分享此文件