在Android上隐藏底部导航视图

Question

我正在开发一个遵循单一活动模式的 Android 应用。在我的一个片段中，我有一个 RecyclerView，在用户向下滚动的情况下，我想隐藏我的 BottomNavigationView。

我已经看过关于这个问题的其他帖子，但似乎没有一个可以帮助我解决我的问题。到目前为止，我已经尝试制作 CoordinatorLayout 的底部导航视图和我的主机片段子级，以及在我的 BottomNavigationView 上添加app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior" 属性。我也尝试在代码中手动实现此行为，但这也不起作用。

这是我的 activity.xml，其中包含我的 BottomNavigationView 和我的主机片段。

<?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"
    xmlns:tools="http://schemas.android.com/tools">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".ui.MainActivity">

        <fragment
            android:id="@+id/fragmentMaster"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:defaultNavHost="true"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintBottom_toTopOf="@id/bottomNav"
            app:layout_constraintTop_toTopOf="parent"
            app:navGraph="@navigation/nav_graph" />

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottomNav"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:menu="@menu/menu_bottom_nav">

        </com.google.android.material.bottomnavigation.BottomNavigationView>

    </androidx.constraintlayout.widget.ConstraintLayout>

</layout>

这是带有 RecyclerView 的片段

<?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"
    xmlns:tools="http://schemas.android.com/tools">

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.appbar.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.google.android.material.appbar.MaterialToolbar
                android:id="@+id/topAppBar"
                style="@style/Widget.MaterialComponents.Toolbar.Primary"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_scrollFlags="scroll"
                app:title="@string/app_name" />

            <HorizontalScrollView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="#FFFFFF"
                android:scrollbars="none"
                app:layout_scrollFlags="scroll">

                <com.google.android.material.chip.ChipGroup
                    android:id="@+id/filterChips"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:padding="8dp"
                    app:singleLine="true">

                    <com.google.android.material.chip.Chip
                        android:id="@+id/breakfastChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/breakfast" />

                    <com.google.android.material.chip.Chip
                        android:id="@+id/mealChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/meal" />

                    <com.google.android.material.chip.Chip
                        android:id="@+id/dinnerChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/dinner" />

                    <com.google.android.material.chip.Chip
                        android:id="@+id/veganChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/vegan" />

                    <com.google.android.material.chip.Chip
                        android:id="@+id/vegetarianChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/vegetarian" />

                    <com.google.android.material.chip.Chip
                        android:id="@+id/regularChip"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:checkable="true"
                        android:text="@string/regular" />

                </com.google.android.material.chip.ChipGroup>

            </HorizontalScrollView>

        </com.google.android.material.appbar.AppBarLayout>

        
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recipeList"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            tools:listitem="@layout/item_recipe_list">
        </androidx.recyclerview.widget.RecyclerView>


        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/newRecipeBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:layout_marginEnd="8dp"
            android:layout_marginBottom="8dp"
            android:contentDescription="@string/add_recipe"
            android:src="@drawable/ic_baseline_add_24">

        </com.google.android.material.floatingactionbutton.FloatingActionButton>

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</layout>

编辑：问题在于内部 CoordinatorLayout 正在消耗滚动事件，因此 AppBarLayout 可以按预期工作，但管理 BottomNavView 的外部 CoordinatorLayout 从未收到滚动通知。解决方案是覆盖 CoordinatorLayout 实现，使其传播到父 CoordinatorLayout。

Answer 1

预览

创建 kotlin 类NavigationViewBehavior.kt

import android.view.View
import androidx.coordinatorlayout.widget.CoordinatorLayout
import androidx.core.view.ViewCompat
import androidx.core.view.ViewCompat.NestedScrollType
import com.google.android.material.bottomnavigation.BottomNavigationView

class NavigationViewBehavior : CoordinatorLayout.Behavior<BottomNavigationView>() {
    private var height = 0
    override fun onLayoutChild(parent: CoordinatorLayout, child: BottomNavigationView, layoutDirection: Int): Boolean {
        height = child.height
        return super.onLayoutChild(parent, child, layoutDirection)
    }

    override fun onStartNestedScroll(coordinatorLayout: CoordinatorLayout,
                                     child: BottomNavigationView, directTargetChild: View, target: View,
                                     axes: Int, type: Int): Boolean {
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL
    }

    override fun onNestedScroll(coordinatorLayout: CoordinatorLayout, child: BottomNavigationView,
                                target: View, dxConsumed: Int, dyConsumed: Int,
                                dxUnconsumed: Int, dyUnconsumed: Int,
                                @NestedScrollType type: Int) {
        if (dyConsumed > 0) {
            slideDown(child)
        } else if (dyConsumed < 0) {
            slideUp(child)
        }
    }

    private fun slideUp(child: BottomNavigationView) {
        child.clearAnimation()
        child.animate().translationY(0f).duration = 200
    }

    private fun slideDown(child: BottomNavigationView) {
        child.clearAnimation()
        child.animate().translationY(height.toFloat()).duration = 200
    }
}

activity_main.xml

    <?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/business_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:hardwareAccelerated="true">

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/coordinator_business_layout"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">


        <FrameLayout
            android:id="@+id/frame_main"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginBottom="?actionBarSize"
            android:orientation="vertical">


            <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:navGraph="@navigation/mobile_navigation"
                tools:ignore="FragmentTagUsage" />

        </FrameLayout>

       

        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/nav_view"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="bottom"
            android:background="@color/colorWhite"
            app:itemBackground="@drawable/border_bottom_ver"
            app:itemIconTint="@drawable/tab_color"
            app:itemTextColor="@drawable/tab_color"
            app:menu="@menu/bottom_nav_menu" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

致电MainActivity.kt

val navController = Navigation.findNavController(this,
                    R.id.nav_host_fragment)
            NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration!!)
            NavigationUI.setupWithNavController(navView!!, navController)
            val layoutParams = navView!!.getLayoutParams() as CoordinatorLayout.LayoutParams
            layoutParams.behavior = NavigationViewBehavior()
            val params = frameLayout.layoutParams as ViewGroup.MarginLayoutParams

            //hide bottom navigation no need while sun activities are being used
            navController.addOnDestinationChangedListener { controller: NavController?,
                                                            destination: NavDestination, arguments: Bundle? ->
                if (destination.id == R.id.navigation_fragments ) {
                    params.setMargins(0, 0, 0, 0)
                    frameLayout.layoutParams = params
                    navView!!.setVisibility(View.GONE)
                } else {
                    params.setMargins(0, 0, 0, 160)
                    frameLayout.layoutParams = params
                    navView!!.setVisibility(View.VISIBLE)
                }
            }

home_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rvServices"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical"
        android:visibility="visible" />

    <TextView
        android:id="@+id/no_values_assigned_message"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:text="@string/no_values_assigned"
        android:textSize="@dimen/fontSizeReg"
        android:textStyle="bold"
        android:visibility="gone" />

</androidx.constraintlayout.widget.ConstraintLayout>

这是我的 RecyclerView 的设置

private fun RecyclerSetting(view: View) {
        no_value = view.findViewById(R.id.no_values_assigned_message)
        rvItem = view.findViewById(R.id.rvServices)
        rvItem!!.setHasFixedSize(true)

        //Very IMP This Line
        val manager = GridLayoutManager(activity, 2,
                GridLayoutManager.VERTICAL,
                false)
        data
        rvItem!!.setLayoutManager(manager)
    }

当您滚动回收站视图时自动隐藏，您还可以隐藏包含特定片段代码的底部导航