/**
 * @author JayChan
 * @desc AppBarLayout快速滑动导致回弹的解决方案,在AppBarLayout的布局里使用这个Behavior即可
 * @date 2018/12/25  10:30
 */
public class AppBarLayoutBehavior extends AppBarLayout.Behavior {
    private static final int TYPE_FLING = 1;

    private boolean isFlinging;
    private boolean shouldBlockNestedScroll;

    public AppBarLayoutBehavior() {
    }

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

    @Override
    public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) {
        KLog.i("AppBarLayoutBehavior", "onInterceptTouchEvent:" + child.getTotalScrollRange());
        shouldBlockNestedScroll = false;
        if (isFlinging) {
            shouldBlockNestedScroll = true;
        }
        return super.onInterceptTouchEvent(parent, child, ev);
    }

    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed, int type) {
        //注意看ViewCompat.TYPE_TOUCH
        KLog.i("AppBarLayoutBehavior", "onNestedPreScroll:" + child.getTotalScrollRange() + " ,dx:" + dx + " ,dy:" + dy + " ,type:" + type);

        //返回1时，表示当前target处于非touch的滑动，
        //该bug的引起是因为appbar在滑动时，CoordinatorLayout内的实现NestedScrollingChild2接口的滑动子类还未结束其自身的fling
        //所以这里监听子类的非touch时的滑动，然后block掉滑动事件传递给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) {
        KLog.i("AppBarLayoutBehavior", "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) {
        super.onStopNestedScroll(coordinatorLayout, abl, target, type);
        isFlinging = false;
        shouldBlockNestedScroll = false;
    }
}

在布局文件中引用

clipboard.png