当滚动底部导航栏不隐藏时 - BottomNavigationBehavior

Question

我想隐藏底部导航栏所以我使用底部导航行为当我有其他代码时它可以工作但是在这里它似乎不起作用我试过但底部导航栏不会隐藏这是代码

 package com.blipclap.creativegraphy.Helper;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;

import static java.lang.Float.parseFloat;

public class BottomNavigationBehaviour extends CoordinatorLayout.Behavior {

    public BottomNavigationBehaviour() {
    }

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

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

    @Override
    public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull View child, @NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
        child.setTranslationY(Math.max(0f,
                Math.min(Float.parseFloat(String.valueOf(child.getHeight())),child.getTranslationY()+dyConsumed)));
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {
        if (dependency instanceof Snackbar.SnackbarLayout)
            updateSnackbar(child,dependency);
        return super.layoutDependsOn(parent, child, dependency);
    }

    private void updateSnackbar(View child, View dependency) {
        if (dependency.getLayoutParams()instanceof CoordinatorLayout.LayoutParams) {
            CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) dependency.getLayoutParams();

            params.setAnchorId(child.getId());
            params.anchorGravity= Gravity.TOP;
            params.gravity=Gravity.TOP;
            dependency.setLayoutParams(params);

        }
    }
}

这是我的布局内容布局我尝试更改相对布局但不幸的是应用程序停止了所以我无法更改它

<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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.blipclap.creativegraphy.HomeActivity"
    tools:showIn="@layout/app_bar_home">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/white">

        <android.support.design.widget.TabLayout
            android:id="@+id/tabLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"></android.support.design.widget.TabLayout>

        <android.support.v4.view.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layoutManager="android.support.v7.widget.LinearLayoutManager"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            android:layout_above="@+id/navigation"
            android:layout_below="@+id/tabLayout"></android.support.v4.view.ViewPager>

        <android.support.design.widget.BottomNavigationView
            android:id="@+id/navigation"
            android:layout_gravity="bottom"
            app:layout_behavior=".Helper.BottomNavigationBehavior"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="@color/colorPrimary"
            app:itemIconTint="@android:color/background_dark"
            app:itemTextColor="@android:color/background_dark"
            app:menu="@menu/bottom_navigation_menu"></android.support.design.widget.BottomNavigationView>
    </RelativeLayout>

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

这是我滚动底部导航栏不隐藏时使用的 3 个片段类别

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.blipclap.creativegraphy.Fragment.CategoryFragment">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_category"
        app:layoutManager="android.support.v7.widget.LinearLayoutManager"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

</RelativeLayout>

每日热门

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.blipclap.creativegraphy.Fragment.CategoryFragment">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_trending"
        app:layoutManager="android.support.v7.widget.LinearLayoutManager"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

</RelativeLayout>

最近

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.blipclap.creativegraphy.Fragment.CategoryFragment">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_recent"
        app:layoutManager="android.support.v7.widget.LinearLayoutManager"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

</RelativeLayout>

这段代码对我不起作用我应该怎么做任何解决方案

参考

bottom navigation behavior reference 1

bottom navigation behavior reference 2

bottom navigation behavior reference 3

我关注了最后一个，但它不起作用

Answer 1

有两件事：

1) 你不应该覆盖 onNestedScroll，它应该是 onNestedPreScroll，删除 onNestedScroll 并将其替换为：

@Override
public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull View child, @NonNull View target, int dx, int dy, @NonNull int[] consumed, int type) {
    super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
    child.setTranslationY(Math.max(0f,
            Math.min(Float.parseFloat(String.valueOf(child.getHeight())),child.getTranslationY()+dy)));
}

2) 在你的 XML 文件中，你把

app:layout_behavior=".Helper.BottomNavigationBehavior"

你的 class 名字是

BottomNavigationBehaviour

如你所见，一个是Behaviour，另一个是Behavior，正常情况下应该抛出一个运行时间错误，应用程序不应该运行，这可能是你的错字，但我提到它是为了以防万一。

但请注意此代码有一个错误，如果您尝试一直向下或向上滚动，RecyclerView 项目将在几秒钟内无法点击，我有一个 similar bug. For now, my choice is to use animation to hide the BottomNavigationView as explained in post.

编辑：

可能没有应用该行为，因为 BottomNavigationView 不是 CoordinatorLayout 的直接子代，因此您可以完全删除 RelativeLayout 或采用 BottomNavigationView出：

<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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.blipclap.creativegraphy.HomeActivity"
    tools:showIn="@layout/app_bar_home">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/white">

        <android.support.design.widget.TabLayout
            android:id="@+id/tabLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"></android.support.design.widget.TabLayout>

        <android.support.v4.view.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layoutManager="android.support.v7.widget.LinearLayoutManager"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            android:layout_above="@+id/navigation"
            android:layout_below="@+id/tabLayout"></android.support.v4.view.ViewPager>


    </RelativeLayout>


    <android.support.design.widget.BottomNavigationView
            android:id="@+id/navigation"
            android:layout_gravity="bottom"
            app:layout_behavior=".Helper.BottomNavigationBehavior"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:background="@color/colorPrimary"
            app:itemIconTint="@android:color/background_dark"
            app:itemTextColor="@android:color/background_dark"
            app:menu="@menu/bottom_navigation_menu">

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

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

Answer 2

BottomLayoutBehavior.java

package com.utility.behaviour;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.NonNull;
import androidx.coordinatorlayout.widget.CoordinatorLayout;
import androidx.core.view.ViewCompat;

public class BottomLayoutBehavior<V extends View> extends CoordinatorLayout.Behavior<V> {

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

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

    @Override
    public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull V child,
                                  @NonNull View target, int dx, int dy, @NonNull int[] consumed, int type) {
        child.setTranslationY(Math.max(0f, Math.min(child.getHeight(), child.getTranslationY() + dy)));
        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
    }
}

activity_main.xml

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

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

        <include layout="@layout/app_bar" />
    </com.google.android.material.appbar.AppBarLayout>

    <com.utility.viewpager.SwipeOnOffViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bnvHome"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="@color/white"
        app:itemIconTint="@color/home_tab_bg"
        app:itemTextColor="@color/home_tab_bg"
        app:labelVisibilityMode="labeled"
        app:layout_anchorGravity="center"
        app:layout_behavior="com.utility.behaviour.BottomLayoutBehavior"
        app:menu="@menu/home_bottom_navigation_items" />
    <!--app:itemBackground="@drawable/home_bottom_bar_gap"-->
</androidx.coordinatorlayout.widget.CoordinatorLayout>

注意：android:layout_gravity="bottom" & app:layout_behavior="com.utility.behaviour.BottomLayoutBehavior" 是强制性的。

当滚动底部导航栏不隐藏时 - BottomNavigationBehavior

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