android - 滚动时 fragment 内容隐藏在 BottomNavigationView 后面

Question

我对此进行了大量研究，但不知道该怎么做 - 我在 fragment 中有一些内容被 Activity 中的 BottomNavigation 栏剪掉了，我不确定该怎么做。我已经尝试将 app:layout_behavior="@string/appbar_scrolling_view_behavior" 添加到 NestedScrollView 但内容的底部(位置名称)仍然被切断 - 可能有一个简单的修复为此，但我无法弄清楚。我的主要 Activity 和“主页” fragment 的 XML 如下:

activity_home.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/home_screen"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <include layout="@layout/app_bar" />

    <FrameLayout
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/bottom_nav"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="start"
        android:background="@color/navbarBackground"
        app:menu="@menu/bottom_nav_menu" />
</LinearLayout>

home_fragment.xml

<?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:id="@+id/home_fragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="0dp">

    <ImageView
        android:id="@+id/tokyo_placeholder"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:adjustViewBounds="true"
        android:scaleType="fitStart"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/main_screen_placeholder" />

    <ImageView
        android:id="@+id/airplane_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/circle_background"
        app:layout_constraintBottom_toBottomOf="@+id/tokyo_placeholder"
        app:layout_constraintLeft_toLeftOf="@+id/tokyo_placeholder"
        app:layout_constraintRight_toRightOf="@+id/tokyo_placeholder"
        app:layout_constraintTop_toTopOf="@+id/tokyo_placeholder"
        app:srcCompat="@drawable/icons8_airplane_48"
        tools:layout_constraintBottom_creator="1"
        tools:layout_constraintLeft_creator="1"
        tools:layout_constraintRight_creator="1"
        tools:layout_constraintTop_creator="1" />

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/scroll_view"
        android:layout_width="0dp"
        android:layout_height="286dp"
        android:layout_marginBottom="@dimen/app_bar_height"
        android:layout_marginStart="5dp"
        android:layout_marginTop="5dp"
        android:fillViewport="true"
        app:layout_constraintBottom_toTopOf="@id/bottom_nav"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tokyo_placeholder"
        tools:layout_constraintLeft_creator="1"
        tools:layout_constraintRight_creator="1">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <TextView
                android:id="@+id/destination_headline"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="@string/featured_destinations_headline"
                android:textAllCaps="true"
                android:textAppearance="@style/TextAppearance.AppCompat.Headline"
                android:textSize="14sp"
                android:textStyle="bold" />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/featured_destinations_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/destination_headline" />

            <TextView
                android:id="@+id/saved_trips_headline"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/featured_destinations_recycler_view"
                android:fontFamily="sans-serif"
                android:text="@string/saved_trips"
                android:textAllCaps="true"
                android:textAppearance="@style/TextAppearance.AppCompat.Headline"
                android:textSize="14sp"
                android:textStyle="bold" />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/saved_trips_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_below="@id/saved_trips_headline" />
        </RelativeLayout>
    </android.support.v4.widget.NestedScrollView>
</android.support.constraint.ConstraintLayout>

app_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:elevation="4dp"
    android:background="#fff"
    android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
    android:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

作为一个例子来说明我的意思，here is the content when the navigation bar is moved out of the way和 here is the content with the bar in the way .我认为问题是某种边距/填充问题，但无法完全弄清楚要解决的问题。

编辑:我已经用相关代码(和一个可行的模拟器示例)创建了一个存储库here - 请注意，代码是用 Kotlin 编写的，但我认为问题不在于任何实际代码，而更多在于布局

Answer 1

我不确定预期的行为是什么，仅通过阅读您的问题我无法理解。已申请this patch ，其中仅包含 home_fragment.xml 布局更改:

<?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:id="@+id/home_fragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="0dp">

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

        <ImageView
            android:id="@+id/tokyo_placeholder"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:scaleType="fitStart"
            app:srcCompat="@drawable/main_screen_placeholder"
            tools:ignore="ContentDescription" />

        <ImageView
            android:id="@+id/airplane_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal|center_vertical"
            android:background="@drawable/circle_background"
            app:srcCompat="@drawable/icons8_airplane_48"
            tools:ignore="ContentDescription" />
    </FrameLayout>

    <android.support.v4.widget.NestedScrollView
        android:id="@+id/scroll_view"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:fillViewport="true"
        android:paddingLeft="5dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/header_container">

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <TextView
                android:id="@+id/destination_headline"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="@string/featured_destinations_headline"
                android:textAllCaps="true"
                android:textAppearance="@style/TextAppearance.AppCompat.Headline"
                android:textSize="14sp"
                android:textStyle="bold" />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/featured_destinations_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_below="@id/destination_headline"
                app:layout_constraintBottom_toTopOf="@id/saved_trips_headline"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/destination_headline" />

            <TextView
                android:id="@+id/saved_trips_headline"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:fontFamily="sans-serif"
                android:text="@string/saved_trips"
                android:textAllCaps="true"
                android:textAppearance="@style/TextAppearance.AppCompat.Headline"
                android:textSize="14sp"
                android:textStyle="bold"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintBottom_toTopOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toBottomOf="@id/featured_destinations_recycler_view" />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/saved_trips_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:layout_constraintBottom_toTopOf="@id/app_bar"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toBottomOf="@id/saved_trips_headline" />
        </android.support.constraint.ConstraintLayout>
    </android.support.v4.widget.NestedScrollView>
</android.support.constraint.ConstraintLayout>

然后你会得到这个输出: