android - 滚动时 BottomNavigationView 不隐藏

Question

我正在开发一个 android 应用程序，其中定义了以下布局以显示顶部导航 View 、抽屉和底部导航 View 。但是，当滚动 recyclerview 中的项目时，我无法隐藏我的 bottomnavigationview。

根据可用的帮助，我已将 app:layout_behavior="@string/hide_bottom_view_on_scroll_behavior" 放在 BottomNavigationView 中，但它看起来比 BottomNavigationView 位于 ConstraintLayout，它没有按预期工作。

我也尝试过使用 CoordinatorLayout 代替 ConstraintLayout，但它不起作用，当我这样做时我的应用挂起。

我也尝试过使用嵌套在 ConstraintLayout 中的 CoordinatorLayout，但我的应用程序在这里也挂起。

感谢任何帮助。 content_dashboard.xml 代码如下:

<?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=".DashboardActivity"
    tools:showIn="@layout/app_bar_dashboard">

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="?android:attr/windowBackground"
        android:foreground="?attr/selectableItemBackground"
        app:itemBackground="@color/bgBottomNavigation"
        app:itemIconTint="@android:color/white"
        app:itemTextColor="@android:color/white"
        app:menu="@menu/menu_bottom_navigation"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_behavior="@string/hide_bottom_view_on_scroll_behavior"/>

</android.support.constraint.ConstraintLayout>

app_bar_dashboard.xml内容如下:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    tools:context="com.mobiapp.hospmgmt.DashboardActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

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


</android.support.design.widget.CoordinatorLayout>

我插入了以下自定义代码来隐藏 BottomNavigationView，但应用挂起。任何建议。

package com.mobiapp.hospmgmt;

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.View;
import android.widget.FrameLayout;

public class BottomNavigationBehaviour extends CoordinatorLayout.Behavior<BottomNavigationView> {

    public BottomNavigationBehaviour() {
        super();
    }

    public BottomNavigationBehaviour(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, BottomNavigationView child, View dependency) {
        boolean dependsOn = dependency instanceof FrameLayout;
        return dependsOn;
    }

    @Override
    public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, BottomNavigationView child, @NonNull View directTargetChild, @NonNull View target, int nestedScrollAxes, int type)
    {
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
    }

    @Override
    public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull BottomNavigationView child, @NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed,
                               @ViewCompat.NestedScrollType int type)
    {
        if (dyConsumed > 0) {
            hideBottomNavigationView(child);
        } else if (dyConsumed < 0) {
            showBottomNavigationView(child);
        }
    }


    private void hideBottomNavigationView(BottomNavigationView view) {
        view.animate().translationY(view.getHeight());
    }

    private void showBottomNavigationView(BottomNavigationView view) {
        view.animate().translationY(0);
    }
}

Answer 1

要使其正常工作，您必须将 BottomNavigationView 作为 CoordinatorLayout 布局的直接子级。修改您的布局，如下所示:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
         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">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.AppBarLayout>

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

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="?android:attr/windowBackground"
        android:foreground="?attr/selectableItemBackground"
        app:itemBackground="@color/bgBottomNavigation"
        app:itemIconTint="@android:color/white"
        app:itemTextColor="@android:color/white"
        app:menu="@menu/menu_bottom_navigation"
        app:layout_behavior="@string/hide_bottom_view_on_scroll_behavior"/>
</android.support.design.widget.CoordinatorLayout>

将 ConstraintLayout 作为 @layout/content_dashboard 的根，然后将 RecyclerView 和其他 View 放在那里:

<?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"
    tools:showIn="@layout/app_bar_dashboard">

    <android.support.v7.widget.RecyclerView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:id="@+id/recycler"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layoutManager="android.support.v7.widget.LinearLayoutManager"
        />
        ....
        ....
</android.support.constraint.ConstraintLayout>