RecyclerView在AppBarLayout滚动时惯性滑动引起卡顿

Question

RecyclerView在AppBarLayout滚动时惯性滑动引起卡顿

5

我有以下的布局。

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">


    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_behavior=".AppBarFlingBehavior">

        <android.support.design.widget.CollapsingToolbarLayout
            android:layout_width="match_parent"
            android:layout_height="300dp"
            app:layout_scrollFlags="scroll|enterAlwaysCollapsed">


            <ImageView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_collapseMode="parallax"
                android:background="#ff99"/>


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


        <TextView
            android:layout_width="match_parent"
            android:layout_height="200dp"
            app:layout_scrollFlags="scroll|enterAlwaysCollapsed"
            android:text="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"/>


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


    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv_sample"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="android.support.design.widget.AppBarLayout$ScrollingViewBehavior"/>


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

我的问题是，当我向下滑动我的AppBarLayout时，内容被滚动，突然，我向上滑动RecyclerView，整个布局会有点卡顿，然后按照RecyclerView的滑动方向(UP)向上滚动，就像您在这个视频中看到的那样。我已经尝试了许多解决方案（自定义行为）来自许多来源，但到目前为止都没有起作用。是否有任何方法可以解决我的问题，我被卡在这里已经有一个星期了。非常感谢您花时间关注我的问题。感激不尽。

- Krot

我也遇到了同样的问题。你在这段时间里找到解决方案了吗？ - Vkay

你找到解决方案了吗？ - Raman Branavitski

@RamanBranavitski 我已经尝试了Vkay的解决方案，它完美地解决了问题，我认为这是目前最好的解决方案。 - Krot

2个回答

0

将您的RecyclerView放置在NestedScrollView中，并从RecyclerView中删除app:layout_behavior，然后为RecyclerView设置android:nestedScrollingEnabled="false"，如下所示 -

<android.support.v4.widget.NestedScrollView 
    android:layout_width="match_parent"
    android:layout_height="match_parent"

       <android.support.v7.widget.RecyclerView
        android:id="@+id/rv_sample"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:nestedScrollingEnabled="false"/>

    </LinearLayout>

</android.support.v4.widget.NestedScrollView>

它应该可以正常工作！

- Anupam

但是如果没有 android.support.design.widget.AppBarLayout$ScrollingViewBehavior 这个行为，我的 RecyclerView 就无法定位在 AppBarLayout 下方。不管怎样，你的方法仍然会导致 RecyclerView 在向上 fling 时出现卡顿。谢谢。 - Krot

在RecyclerView初始化后，在您的Java代码中使用以下代码：recyclerView.setNestedScrollingEnabled(false); - Anupam

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- Vkay · Accepted Answer

我找到了一个解决方案（感谢yangchong：https://developpaper.com/coordinator-layout-sliding-jitter-problem/）: AppBarBehavior:

/**
 * <pre>
 *     @author yangchong
 *     blog  : https://github.com/yangchong211
 *     time  : 2019/03/13
 * desc: Custom Behavior
 * Revision: Solving Some Problems of AppbarLayout
 * 1) Fast sliding appbarLayout will rebound
 * 2) Fast sliding appbarLayout to fold state, immediately sliding down, there will be the problem of jitter.
 * 3) Slide appbarLayout, unable to stop sliding by pressing it with your finger
*/
public class AppBarLayoutBehavior extends AppBarLayout.Behavior {

    private static final String TAG = "AppbarLayoutBehavior";
    private static final int TYPE_FLING = 1;
    private boolean isFlinging;
    private boolean shouldBlockNestedScroll;

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

    @Override
    public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) {
        LogUtil.d(TAG, "onInterceptTouchEvent:" + child.getTotalScrollRange());
        shouldBlockNestedScroll = isFlinging;
        switch (ev.getActionMasked()) {
            case MotionEvent.ACTION_DOWN:
                // Stop fling when your finger touches the screen
                stopAppbarLayoutFling(child);
                break;
            default:
                break;
        }
        return super.onInterceptTouchEvent(parent, child, ev);
    }

    /**
     * Reflect to get private flingRunnable attributes, considering the problem of variable name modification after support 28
     * @return Field
     * @throws NoSuchFieldException
     */
    private Field getFlingRunnableField() throws NoSuchFieldException {
        Class<?> superclass = this.getClass().getSuperclass();
        try {
            // Support design 27 and the following version
            Class<?> headerBehaviorType = null;
            if (superclass != null) {
                headerBehaviorType = superclass.getSuperclass();
            }
            if (headerBehaviorType != null) {
                return headerBehaviorType.getDeclaredField("mFlingRunnable");
            }else {
                return null;
            }
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
            // Possibly 28 or more versions
            Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass();
            if (headerBehaviorType != null) {
                return headerBehaviorType.getDeclaredField("flingRunnable");
            } else {
                return null;
            }
        }
    }

    /**
     * Reflect to get private scroller attributes, considering the problem of variable name modification after support 28
     * @return Field
     * @throws NoSuchFieldException
     */
    private Field getScrollerField() throws NoSuchFieldException {
        Class<?> superclass = this.getClass().getSuperclass();
        try {
            // Support design 27 and the following version
            Class<?> headerBehaviorType = null;
            if (superclass != null) {
                headerBehaviorType = superclass.getSuperclass();
            }
            if (headerBehaviorType != null) {
                return headerBehaviorType.getDeclaredField("mScroller");
            }else {
                return null;
            }
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
            // Possibly 28 or more versions
            Class<?> headerBehaviorType = superclass.getSuperclass().getSuperclass();
            if (headerBehaviorType != null) {
                return headerBehaviorType.getDeclaredField("scroller");
            }else {
                return null;
            }
        }
    }

    /**
     * Stop appbarLayout's fling event
     * @param appBarLayout
     */
    private void stopAppbarLayoutFling(AppBarLayout appBarLayout) {
        // Get the flingRunnable variable in HeaderBehavior by reflection
        try {
            Field flingRunnableField = getFlingRunnableField();
            Field scrollerField = getScrollerField();
            if (flingRunnableField != null) {
                flingRunnableField.setAccessible(true);
            }
            if (scrollerField != null) {
                scrollerField.setAccessible(true);
            }
            Runnable flingRunnable = null;
            if (flingRunnableField != null) {
                flingRunnable = (Runnable) flingRunnableField.get(this);
            }
            OverScroller overScroller = (OverScroller) scrollerField.get(this);
            if (flingRunnable != null) {
                LogUtil.d (TAG,'Flying Runnable');
                appBarLayout.removeCallbacks(flingRunnable);
                flingRunnableField.set(this, null);
            }
            if (overScroller != null && !overScroller.isFinished()) {
                overScroller.abortAnimation();
            }
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child,
                                       View directTargetChild, View target,
                                       int nestedScrollAxes, int type) {
        LogUtil.d(TAG, "onStartNestedScroll");
        stopAppbarLayoutFling(child);
        return super.onStartNestedScroll(parent, child, directTargetChild, target,
                nestedScrollAxes, type);
    }

    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout,
                                  AppBarLayout child, View target,
                                  int dx, int dy, int[] consumed, int type) {
        LogUtil.d(TAG, "onNestedPreScroll:" + child.getTotalScrollRange()
                + " ,dx:" + dx + " ,dy:" + dy + " ,type:" + type);
        // When type returns to 1, it indicates that the current target is in a non-touch sliding.
        // The bug is caused by the sliding of the NestedScrolling Child2 interface in Coordinator Layout when the AppBar is sliding
        // The subclass has not ended its own fling
        // So here we listen for non-touch sliding of subclasses, and then block the sliding event to AppBarLayout
        if (type == TYPE_FLING) {
            isFlinging = true;
        }
        if (!shouldBlockNestedScroll) {
            super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
        }
    }

    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child,
                               View target, int dxConsumed, int dyConsumed, int
            dxUnconsumed, int dyUnconsumed, int type) {
        LogUtil.d(TAG, "onNestedScroll: target:" + target.getClass() + " ,"
                + child.getTotalScrollRange() + " ,dxConsumed:"
                + dxConsumed + " ,dyConsumed:" + dyConsumed + " " + ",type:" + type);
        if (!shouldBlockNestedScroll) {
            super.onNestedScroll(coordinatorLayout, child, target, dxConsumed,
                    dyConsumed, dxUnconsumed, dyUnconsumed, type);
        }
    }

    @Override
    public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout abl,
                                   View target, int type) {
        LogUtil.d(TAG, "onStopNestedScroll");
        super.onStopNestedScroll(coordinatorLayout, abl, target, type);
        isFlinging = false;
        shouldBlockNestedScroll = false;
    }

    private static class LogUtil{
        static void d(String tag, String string){
            Log.d(tag,string);
        }
    }

}