在 Recyclerview 中向下滚动时使布局向下/滑出视图？

Question

我正在尝试实现包含项目的 Recyclerview，并且我在屏幕底部有一个包含 3 个按钮的布局，我想在我开始滚动 Recyclerview 时将其消失或向下滑动。我进行了很多搜索，但找不到任何关于此的内容...我知道如何实现折叠工具栏布局，但是对于底部的布局有什么技巧吗？

<?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"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:id="@+id/c2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"

            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <android.support.v7.widget.RecyclerView
                android:id="@+id/rvContacts"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />




        <com.github.clans.fab.FloatingActionMenu
            android:id="@+id/menu2"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:paddingBottom="10dp"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            fab:menu_backgroundColor="#ccffffff"
            fab:menu_fab_label="Menu label"
            fab:menu_icon="@drawable/filter2"
            fab:menu_labels_ellipsize="end"
            fab:menu_labels_singleLine="true">

            <com.github.clans.fab.FloatingActionButton
                android:id="@+id/fab1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/aa"
                fab:fab_label="Menu item 1"
                fab:fab_size="mini" />

            <com.github.clans.fab.FloatingActionButton
                android:id="@+id/fab2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/aa"
                fab:fab_label="Menu item 2"
                fab:fab_size="mini" />

            <com.github.clans.fab.FloatingActionButton
                android:id="@+id/fab3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/aa"
                fab:fab_label="Menu item 3"
                fab:fab_size="mini" />

        </com.github.clans.fab.FloatingActionMenu>

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="#e7e7e7"
        android:gravity="bottom"
        android:orientation="horizontal"
        android:weightSum="3">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1">

            <TextView
                android:id="@+id/allbrands"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="All Brands"
                android:textSize="10dp" />


        </RelativeLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:orientation="vertical"
            android:weightSum="2">

            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="0.8">

                <ImageView
                    android:id="@+id/brandsearch"
                    android:layout_width="32dp"
                    android:layout_height="32dp"
                    android:layout_centerInParent="true"
                    android:src="@drawable/search01"

                    />
            </RelativeLayout>

            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1.2">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:gravity="center|top"
                    android:text="Search Brands"
                    android:textSize="10dp" />


            </RelativeLayout>


        </LinearLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1">

            <TextView
                android:id="@+id/allposts"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerInParent="true"
                android:text="All Posts"
                android:textSize="10dp" />
        </RelativeLayout>


    </LinearLayout>
</LinearLayout>

Answer 1

创建一个滚动监听器并添加到RecyclerView

public abstract class HidingScrollListener extends RecyclerView.OnScrollListener {

    public boolean mControlsVisible = true;
    private int HIDE_THRESHOLD = 50;
    private int mScrolledDistance = 0;

    public HidingScrollListener(int threshold) {
        this.HIDE_THRESHOLD = threshold;
    }

    private HidingScrollListener() {
    }

    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);

        int firstVisibleItem = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstVisibleItemPosition();
        if (firstVisibleItem == 0) {
            if (!mControlsVisible) {
                onShow();
                mControlsVisible = true;
            }
        } else {
        if (mScrolledDistance > HIDE_THRESHOLD && mControlsVisible) {
            onHide();
            mControlsVisible = false;
            mScrolledDistance = 0;
        } else if (mScrolledDistance < -HIDE_THRESHOLD && !mControlsVisible) {
            onShow();
            mControlsVisible = true;
            mScrolledDistance = 0;
        }
        }
        if ((mControlsVisible && dy > 0) || (!mControlsVisible && dy < 0)) {
            mScrolledDistance += dy;
        }
    }

    public void resetScrollDistance() {
        mControlsVisible = true;
        mScrolledDistance = 0;
    }

    public abstract void onHide();

    public abstract void onShow();
}

初始化监听器

int threshold = 50;
        listener = new HidingScrollListener(threshold) {
            @Override
            public void onHide() {
                hideViews();
            }

            @Override
            public void onShow() {
                showViews();
            }
        };

yourListView.addOnScrollListener(listener);

实现显示和隐藏视图方法

public void showViews() {
        listener.resetScrollDistance();
        view.animate().translationY(0).setInterpolator(new DecelerateInterpolator(2)).setDuration(ANIMATION_DURATION);
    }

    public void hideViews() {
        view.animate().translationY(view.getHeight()).setInterpolator(new AccelerateInterpolator(2)).setDuration(ANIMATION_DURATION);

    }

单独调整 translationY 值