本文主要针对两个问题进行说明：
- 横向rv和viewpager滚动冲突
- rv滚动到底部监听
首先我们写一个自定义的rv
public class DefRecylerView extends RecyclerView {
public DefRecylerView(Context context) {
super(context);
}
public DefRecylerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public DefRecylerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
}
- rv、viewpager滚动冲突
当遇到外层viewpager里面有一个横向滚动的rv，为防止rv滚动到最右侧时触发viewpager的滚动我们需要这样做:
private ViewPager viewPager = null;
public void setViewPager(ViewPager viewPager) {
this.viewPager = viewPager;
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
if (viewPager != null) {
getParent().requestDisallowInterceptTouchEvent(true);
}
return super.dispatchTouchEvent(ev);
}
我们在自定义的rv中重写dispatchTouchEvent方法，最为核心的一句代码为:
getParent().requestDisallowInterceptTouchEvent(true);
意思是当外层view是viewpager时，我们取消viewpager对滚动事件的拦截，让滚动事件继续往下传递到rv，从而实现了横向rv滚动到最右侧时不触发viewpager的滚动。
- rv滚动到底部监听
自定义rv中重写onScroll方法,定义一个回调接口，当rv滚动到底部时回调通知，适用于列表数据加载更多操作。
回调接口：
public interface OnSlideBottomListener {
/**
* 滚动到底部
*/
void onSlideBottom();
}
重写onScroll：
private OnSlideBottomListener onSlideBottomListener = null;
public void setOnSlideBottomListener(OnSlideBottomListener onSlideBottomListener) {
this.onSlideBottomListener = onSlideBottomListener;
}
@Override
public void onScrolled(int dx, int dy) {
if (isSlideToBottom()) {
if (onSlideBottomListener != null) {
onSlideBottomListener.onSlideBottom();
}
}
}
/**
* 是否滑动到底部
*/
public boolean isSlideToBottom() {
if (this.getLayoutManager() instanceof LinearLayoutManager) {
LinearLayoutManager layoutManager = (LinearLayoutManager) this.getLayoutManager();
if (layoutManager.getOrientation() == LinearLayoutManager.VERTICAL) {
return this != null
&& this.computeVerticalScrollExtent() + this.computeVerticalScrollOffset()
>= this.computeVerticalScrollRange();
} else {
return this != null
&& this.computeHorizontalScrollExtent() + this.computeHorizontalScrollOffset()
>= this.computeHorizontalScrollRange();
}
} else if(this.getLayoutManager() instanceof StaggeredGridLayoutManager){
StaggeredGridLayoutManager layoutManager = (StaggeredGridLayoutManager) this.getLayoutManager();
if (layoutManager.getOrientation() == StaggeredGridLayoutManager.VERTICAL) {
return this != null
&& this.computeVerticalScrollExtent() + this.computeVerticalScrollOffset()
>= this.computeVerticalScrollRange();
} else {
return this != null
&& this.computeHorizontalScrollExtent() + this.computeHorizontalScrollOffset()
>= this.computeHorizontalScrollRange();
}
}
return false;
}
