CoordinatorLayout实现自定义头条卡住的解决方案

废话不多说，直接上代码，xml布局如下：

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/color_ffffff">
    <!--互动详情页面布局-->
    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/color_f1f1f6"
        android:stateListAnimator="@null"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:layout_behavior=".view.FlingBehavior">

        <android.support.design.widget.CollapsingToolbarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:minHeight="?actionBarSize"
            app:contentScrim="@color/color_ffffff"
            app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">

            <!-- 背景图 -->
            <ImageView
                android:id="@+id/ivBackGround"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:src="@drawable/bg_lesson"
                app:layout_collapseMode="parallax" />

            <!-- 内容 -->
            <LinearLayout
                android:id="@+id/llTitleContent"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="@dimen/s_50dp"
                android:orientation="vertical"
                app:layout_collapseMode="parallax">
                <!--app:layout_collapseParallaxMultiplier="0.7"-->
                <TextView
                    android:id="@+id/tvDetailName"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/s_15dp"
                    android:layout_marginRight="@dimen/s_15dp"
                    android:lineSpacingExtra="@dimen/s_4dp"
                    android:text="@string/str_place_holder"
                    android:textColor="@color/color_333333"
                    android:textSize="@dimen/s_18sp"
                    android:textStyle="bold" />

                <TextView
                    android:id="@+id/tvClassName"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/s_15dp"
                    android:layout_marginTop="@dimen/s_12dp"
                    android:layout_marginRight="@dimen/s_15dp"
                    android:text="@string/str_place_holder"
                    android:textColor="@color/color_666666"
                    android:textSize="@dimen/s_14sp"
                    android:textStyle="normal" />
                <!--str_release_class-->

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/s_15dp"
                    android:layout_marginRight="@dimen/s_15dp"
                    android:orientation="horizontal">

                    <TextView
                        android:id="@+id/tvAccessCode"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="@string/str_place_holder"
                        android:textColor="@color/color_666666"
                        android:textSize="@dimen/s_14sp"
                        android:textStyle="normal" />
                    <!--str_assess_code-->

                    <TextView
                        android:id="@+id/tvCopyAccessCode"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:paddingLeft="@dimen/s_15sp"
                        android:paddingTop="@dimen/s_12dp"
                        android:paddingRight="@dimen/s_15sp"
                        android:paddingBottom="@dimen/s_12dp"
                        android:text="复制"
                        android:textColor="@color/color_2b96ff"
                        android:textSize="@dimen/s_14sp" />
                </LinearLayout>

                <RelativeLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/s_15dp"
                    android:layout_marginRight="@dimen/s_15dp"
                    android:layout_marginBottom="@dimen/s_20dp">

                    <TextView
                        android:id="@+id/tvAccessMemberCount"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_centerVertical="true"
                        android:text="0"
                        android:textColor="@color/color_ff9100"
                        android:textSize="@dimen/s_20sp"
                        android:textStyle="bold" />

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignBaseline="@+id/tvAccessMemberCount"
                        android:layout_toRightOf="@+id/tvAccessMemberCount"
                        android:text="人参与"
                        android:textColor="@color/color_666666"
                        android:textSize="@dimen/s_14sp" />

                    <android.support.v7.widget.RecyclerView
                        android:id="@+id/rvAccessMemberList"
                        android:layout_width="wrap_content"
                        android:layout_height="@dimen/s_28dp"
                        android:layout_alignParentRight="true" />
                </RelativeLayout>

                <!--脚下的圆角占位布局-->
                <View
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/s_10dp"
                    android:background="@drawable/shape_ffffff_top_left_right_5dp" />
            </LinearLayout>

            <!-- 一级标题 -->
            <android.support.v7.widget.Toolbar
                android:id="@+id/tbFirstTitle"
                android:layout_width="match_parent"
                android:layout_height="@dimen/s_44dp"
                android:background="@android:color/transparent"
                app:contentInsetStart="0dp"
                app:layout_collapseMode="pin"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/s_44dp"
                    android:orientation="horizontal">

                    <ImageView
                        android:id="@+id/ivBack"
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:paddingLeft="@dimen/s_15dp"
                        android:paddingRight="@dimen/s_15dp"
                        android:src="@drawable/nav_btn_back" />

                    <TextView
                        android:id="@+id/tvTitle"
                        android:layout_width="0dp"
                        android:layout_height="match_parent"
                        android:layout_weight="1"
                        android:gravity="center"
                        android:textColor="@color/color_333333"
                        android:textSize="@dimen/s_18sp"
                        android:textStyle="bold" />

                    <ImageView
                        android:id="@+id/ivShare"
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:paddingLeft="@dimen/s_15dp"
                        android:paddingRight="@dimen/s_15dp"
                        android:src="@drawable/lesson_share_selector"
                        android:visibility="invisible" />
                </LinearLayout>
            </android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>

        <!-- 二级标题 -->
        <RelativeLayout
            android:id="@+id/rlSecondTitle"
            android:layout_width="match_parent"
            android:layout_height="@dimen/s_44dp"
            android:layout_gravity="bottom"
            android:background="@color/color_ffffff">

            <TextView
                android:id="@+id/tvCourseSummary"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/s_15dp"
                android:text="课程小节"
                android:textColor="@color/color_333333"
                android:textSize="@dimen/s_16sp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/tvCount"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_toRightOf="@+id/tvCourseSummary"
                android:text="@string/str_place_holder"
                android:textColor="@color/color_999999"
                android:textSize="@dimen/s_14sp" />
        </RelativeLayout>
    </android.support.design.widget.AppBarLayout>

    <!--单个item布局：layout_interactive_detail_first_item-->
    <!--单个item布局：layout_interactive_detail_second_item-->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvContentList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:nestedScrollingEnabled="true"
        android:orientation="vertical"
        android:overScrollMode="never"
        android:scrollbars="none"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <TextView
        android:id="@+id/tvContentEmpty"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:clickable="false"
        android:drawableTop="@drawable/balnk_file"
        android:drawablePadding="@dimen/s_13dp"
        android:enabled="false"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:gravity="center_horizontal"
        android:nestedScrollingEnabled="true"
        android:paddingTop="@dimen/s_50dp"
        android:paddingBottom="@dimen/s_50dp"
        android:text="暂无内容"
        android:textColor="@color/color_bbbbbb"
        android:textSize="@dimen/s_15sp"
        android:visibility="gone"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>

效果图如下：

展开状态.jpg
收起状态.jpg

需要针对RecyclerView添加滚动监听器，当RecyclerView停下来的时候判定它距离屏幕顶部的高度，然后让appBarLayout执行展开或者收起，这样就能够规避掉RecyclerView和CoordinatorLayout组合发生抖动之后卡住不动的问题，具体代码如下：

// 添加顶部滑动监听器
if (appBarOffsetListener == null) {
    appBarOffsetListener = new AppBarLayout.OnOffsetChangedListener() {
        @Override
        public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
            if (llTitleContent != null && tvTitle != null) {
                if (verticalOffset <= -llTitleContent.getHeight() / 2) {
                    tvTitle.setText("互动课程详情");
                } else {
                    tvTitle.setText("");
                }
            }
        }
    };
}
// 头条发生拖动时，需要变换主标题
appBarLayout.addOnOffsetChangedListener(appBarOffsetListener);
// 设置内容滚动监听器
if (scrollListener == null) {
    scrollListener = new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
            // 如果当前处于空闲状态，那么可以执行判定操作
            if (newState == RecyclerView.SCROLL_STATE_IDLE && rvContentList != null) {
                int[] location = new int[2];
                rvContentList.getLocationInWindow(location);
                // 两个标题栏的高度（一级标题和二级标题的高度） 加上 状态栏的高度就是recyclerView距离屏幕顶部可能到达最近的距离
                float minY = titleHeight * 2 + statusHeight;
                // 如果当前recyclerView距离最高位置小于5个像素，那么认为应该关闭，否则打开
                if (location[1] - minY <= 5) {
                    if (appBarLayout != null) {
                        appBarLayout.setExpanded(false, true);
                    }
                }
                // 否则打开整体布局
                else if (appBarLayout != null) {
                    appBarLayout.setExpanded(true, true);
                }
            }
        }
    };
}
// 添加滚动监听器，防止卡顿的发生
rvContentList.addOnScrollListener(scrollListener);

下面这个FlingBehavior 主要用于解决RecyclerView滑动之后，第一次点击发生失效的问题

import android.content.Context;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.view.View;

/**
 * 用于解决CoordinatorLayout与RecyclerView之间发生的点击问题
 */
public class FlingBehavior extends AppBarLayout.Behavior {

    public FlingBehavior() {
    }

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

    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
        stopNestedScrollIfNeeded(dyUnconsumed, child, target, type);
    }

    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed, int type) {
        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
        stopNestedScrollIfNeeded(dy, child, target, type);
    }

    private void stopNestedScrollIfNeeded(int dy, AppBarLayout child, View target, int type) {
        if (type == ViewCompat.TYPE_NON_TOUCH) {
            final int currOffset = getTopAndBottomOffset();
            if ((dy < 0 && currOffset == 0) || (dy > 0 && currOffset == -child.getTotalScrollRange())) {
                ViewCompat.stopNestedScroll(target, ViewCompat.TYPE_NON_TOUCH);
            }
        }
    }
}