我在我的Android 项目中使用导航组件。我正在使用One Activity 模型并遵循此模型，我有 1 个Base Activity，其余都是Fragments。当我必须移回上一个片段时，
我的问题出现在按下后退按钮。我在名为WorkerAnalyticsFragment的片段中有滚动视图，如下所示。
中心显示的Container包含Scroll 视图作为根视图，用于在展开Order analytics和Motivation analytics以显示详细信息时滚动容器内的内容。fragment_worker_analytics的 xml 代码如下所示。
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
tools:context=".Fragment.WorkerAnalyticsFragment"
android:background="@color/uniform_background">
<LinearLayout
android:id="@+id/profile_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_gravity="center_horizontal"
android:layout_marginTop="@dimen/profile_container_margin_top">
<de.hdodenhof.circleimageview.CircleImageView
android:id="@+id/circle_image_view_large"
android:layout_width="@dimen/circle_image_view_large_width"
android:layout_height="@dimen/circle_image_view_large_height"
android:src="@drawable/example_avatar"
android:layout_gravity="center_horizontal"/>
<androidx.appcompat.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/text_view_profile_name"
android:maxLines="1"
android:layout_gravity="center_horizontal"
style="@style/UniformTextAppearance"/>
</LinearLayout>
<include layout="@layout/analytics_container" android:id="@+id/analytics_container"/>
<include layout="@layout/order_and_report_buttons" android:id="@+id/order_and_report_buttons"/>
</LinearLayout>
</layout>
上图中间的analytics_container的xml代码在这里。
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ScrollView
android:id="@+id/scroll_view"
android:layout_width="match_parent"
android:layout_height="350dp"
android:layout_margin="@dimen/analytics_container_margin"
android:background="@drawable/container_background"
android:minHeight="350dp"
android:scrollbars="none"
android:padding="@dimen/analytics_container_padding">
<LinearLayout
android:id="@+id/analytics_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:id="@+id/current_order_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/text_view_current_order_status_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/text_view_current_order_status_text"
android:textStyle="bold"
style="@style/UniformTextAppearance"/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center">
<LinearLayout
android:id="@+id/current_order_details_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginTop="@dimen/step_view_margin_top"
android:visibility="visible">
<com.kofigyan.stateprogressbar.StateProgressBar
android:id="@+id/order_progress_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:spb_maxStateNumber="four"
app:spb_stateDescriptionSize="@dimen/sbp_state_description_text_size"
app:spb_maxDescriptionLines="1"
app:spb_stateBackgroundColor="@color/spb_state_background_color"
app:spb_stateForegroundColor="@color/spb_state_foreground_color"
app:spb_descriptionTopSpaceIncrementer="@dimen/spb_description_top_Space_incrementer"
app:spb_currentStateDescriptionColor="@color/spb_current_state_description_color"
app:spb_stateDescriptionColor="@color/spb_state_description_color"
app:spb_stateNumberBackgroundColor="@color/spb_state_number_background_color"/>
<include layout="@layout/current_item" android:id="@+id/current_item"/>
</LinearLayout>
<TextView
android:id="@+id/empty_text_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/no_current_order_text"
android:textSize="@dimen/empty_text_size"
android:textStyle="bold"
android:layout_gravity="center"
android:visibility="invisible"
android:background="@color/current_item_container_background_color"
style="@style/EmptyTextAppearance"
/>
</FrameLayout>
</LinearLayout>
<LinearLayout
android:id="@+id/profile_analytics_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginTop="@dimen/profile_container_margin_top">
<TextView
android:id="@+id/text_view_worker_analytics"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/text_view_worker_analytics_text"
android:textStyle="bold"
style="@style/UniformTextAppearance"/>
<include layout="@layout/card_view_analytics_container"/>
</LinearLayout>
</LinearLayout>
</ScrollView>
</layout>
我有另一个名为OrderFragment的片段，当用户单击ORDER按钮时，它会出现，如上图所示。这是图片。
OrderFragment的代码如下所示。
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<LinearLayout
android:id="@+id/stock_fragment_parent_layout_padding"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="@dimen/stock_fragment_parent_layout_padding"
android:background="@color/uniform_background"
tools:context=".Fragment.OrderFragment">
<LinearLayout
android:id="@+id/stock_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
android:orientation="vertical"
android:layout_marginTop="@dimen/stock_container_margin_top"
android:background="@drawable/container_background">
<TextView
android:id="@+id/text_view_available_stock_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="@string/text_view_available_stock_text"
style="@style/UniformTextAppearance"/>
<LinearLayout
android:id="@+id/stock_list_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="@dimen/stock_list_container_margin_top">
<include layout="@layout/recycler_view" android:id="@+id/recycler_view"/>
</LinearLayout>
</LinearLayout>
</LinearLayout>
</layout>
当我按下后退按钮返回到上面通过 xml 代码和图片显示的上一个WorkerAnayticsFragment时，问题就出现了，我的应用程序崩溃了。
这是我的日志猫在应用程序崩溃时显示错误。
2020-03-27 01:26:57.757 20708-20708/com.example.nibotransporti E/AndroidRuntime: FATAL EXCEPTION:
main
Process: com.example.nibotransporti, PID: 20708
java.lang.ClassCastException: android.view.AbsSavedState$1 cannot be cast to
android.widget.ScrollView$SavedState
at android.widget.ScrollView.onRestoreInstanceState(ScrollView.java:1872)
at android.view.View.dispatchRestoreInstanceState(View.java:17819)
at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3773)
at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:3781)
at android.view.View.restoreHierarchyState(View.java:17797)
at androidx.fragment.app.Fragment.restoreViewState(Fragment.java:574)
at androidx.fragment.app.FragmentStateManager.restoreViewState(FragmentStateManager.java:505)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1164)
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2209)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1976)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1915)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1811)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:427)
at android.os.Handler.handleCallback(Handler.java:808)
at android.os.Handler.dispatchMessage(Handler.java:101)
at android.os.Looper.loop(Looper.java:166)
at android.app.ActivityThread.main(ActivityThread.java:7529)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:245)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:921)
2020-03-27 01:26:57.799 20708-20708/com.example.nibotransporti I/Process: Sending signal. PID:
20708 SIG: 9
我遇到了严重的麻烦。请通过建议我一个强大的解决方案来帮助我。