如果你用 CoordinatorLayout 嵌套AppBarLayout RecyclerView，你会发现一个问题，滑动会有卡顿，关键是，你如果一直用手指触碰屏幕滑动的话不会感觉什么。而卡顿是在产生惯性的时候。我们都知道现在的android滑动组件很牛逼，都有惯性的效果，你比如说RecyclerView，你滑动一定速度之后你放开手，它还会以减速的方式滑动一段距离。而这个demo不顺畅的地方就是在放开手之后的惯性上。别人也有遇到过这个问题
一 ：解决CoordinatorLayout滑动卡顿
1. 大屌推荐之自定义Behavior 方法（这是我的布局）
二：我的工具包 utils CustomBehavior
public class CustomBehavior extends AppBarLayout.Behavior {
private static final String TAG = "AppbarLayoutBehavior";
private static final int TYPE_FLING = 1;
/**
* 记录是否有fling
*/
private boolean isFlinging;
/**
* 记录是否
*/
private boolean shouldBlockNestedScroll;
public CustomBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
* 是否拦截触摸事件
* @param parent CoordinatorLayout
* @param child AppBarLayout
* @param ev ev
* @return
*/
@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:
//手指触摸屏幕的时候停止fling事件
stopAppbarLayoutFling(child);
break;
default:
break;
}
return super.onInterceptTouchEvent(parent, child, ev);
}
/**
* 反射获取私有的flingRunnable 属性，考虑support 28以后变量名修改的问题
* @return Field
* @throws NoSuchFieldException
*/
private Field getFlingRunnableField() throws NoSuchFieldException {
Class superclass = this.getClass().getSuperclass();
try {
// support design 27及一下版本
Class headerBehaviorType = null;
if (superclass != null) {
String name = superclass.getName();
LogUtil.d("AppBarLayout.Behavior父类",name);
headerBehaviorType = superclass.getSuperclass();
}
if (headerBehaviorType != null) {
String name = headerBehaviorType.getName();
LogUtil.d("AppBarLayout.Behavior父类的父类1",name);
return headerBehaviorType.getDeclaredField("mFlingRunnable");
}else {
return null;
}
} catch (NoSuchFieldException e) {
e.printStackTrace();
// 可能是28及以上版本
Class headerBehaviorType = superclass.getSuperclass().getSuperclass();
if (headerBehaviorType != null) {
String name = headerBehaviorType.getName();
LogUtil.d("AppBarLayout.Behavior父类的父类2",name);
return headerBehaviorType.getDeclaredField("flingRunnable");
} else {
return null;
}
}
}
/**
* 反射获取私有的scroller 属性，考虑support 28以后变量名修改的问题
* @return Field
* @throws NoSuchFieldException
*/
private Field getScrollerField() throws NoSuchFieldException {
Class superclass = this.getClass().getSuperclass();
try {
// support design 27及一下版本
Class headerBehaviorType = null;
if (superclass != null) {
headerBehaviorType = superclass.getSuperclass();
}
if (headerBehaviorType != null) {
return headerBehaviorType.getDeclaredField("mScroller");
}else {
return null;
}
} catch (NoSuchFieldException e) {
e.printStackTrace();
// 可能是28及以上版本
Class headerBehaviorType = superclass.getSuperclass().getSuperclass();
if (headerBehaviorType != null) {
return headerBehaviorType.getDeclaredField("scroller");
}else {
return null;
}
}
}
/**
* 停止appbarLayout的fling事件
* @param appBarLayout
*/
private void stopAppbarLayoutFling(AppBarLayout appBarLayout) {
//通过反射拿到HeaderBehavior中的flingRunnable变量
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 = null;
if (scrollerField != null) {
overScroller = (OverScroller) scrollerField.get(this);
}
//下面是关键点
if (flingRunnable != null) {
LogUtil.d(TAG, "存在flingRunnable");
appBarLayout.removeCallbacks(flingRunnable);
flingRunnableField.set(this, null);
}
if (overScroller != null && !overScroller.isFinished()) {
overScroller.abortAnimation();
}
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
/**
* 嵌套滑动开始（ACTION_DOWN），确定Behavior是否要监听此次事件
*/
@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);
}
/**
* 嵌套滑动进行中，要监听的子 View将要滑动，滑动事件即将被消费（但最终被谁消费，可以通过代码控制）
*/
@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);
//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);
}
}
/**
* 嵌套滑动进行中，要监听的子 View的滑动事件已经被消费
*/
@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);
}
}
/**
* 嵌套滑动结束（ACTION_UP或ACTION_CANCEL）
*/
@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);
}
}
}
欧克 这样就可以解决这个问题 了
