Android使用NestedScrollView 内嵌RecycleView滑动冲突问题解决

public class CustomScrollView extends NestedScrollView {

    public CustomScrollView(@NonNull Context context) {
        super(context);
    }
    private float maxSlideDis;//向上滑动的最大滑动距离，没有超过这个距离时，拦截并处理掉向上滑动的事件
    //在activity或fragment中，根据布局参数进行设置
    private float mDownY;
    private float mSlop;
    public CustomScrollView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        mSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }
    public void setMaxSlideDis(float maxSlideDis) {
        this.maxSlideDis = maxSlideDis;
    }
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        Logger.log("CustomScrollView onInterceptTouchEvent "   ev.getAction());
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownY = ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                float dis = ev.getRawY() - mDownY;
                if (dis < 0 && Math.abs(dis) >= mSlop) {
                    //当触摸事件是向上滑动并且滑动距离超过屏幕的最小滑动单位时
                    return needScrollParent();
                }
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }
    //scroller 是否已经滑动到了最高点
    public boolean needScrollParent() {
        Logger.log("CustomScrollView maxSlideDis = "   maxSlideDis   " getScrollY ="   getScrollY());
        return getScrollY() < maxSlideDis;
    }
    public CustomScrollView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

}

public boolean dispatchTouchEvent(MotionEvent ev) {
    boolean consume = false;
    if(onInterceptTouchEvent(ev)){
        consume = onTouchEvent(ev);
    } else {
        consume = child.dispatchTouchEvent(ev);
    }
    return consume;
}  

 @Override
 @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        Logger.log("CustomScrollView dispatchTouchEvent ACTION  "   ev.getAction());

        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownY = ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                float dis = ev.getRawY() - mDownY;
                if (dis < 0 && Math.abs(dis) >= mSlop) {
                    //当触摸事件是向上滑动并且滑动距离超过屏幕的最小滑动单位时
                    if (needScrollParent()) {
                        onTouchEvent(ev);
                        Logger.log("dispatchTouchEvent 需要拦截");
                        return true;
                    } else {
                        Logger.log("dispatchTouchEvent 不需要拦截");
                        //这里返回 super.dispatchTouchEvent(ev); 在super.dispatchTouchEvent(ev)中会调用下面的onInterceptTouchEvent 方法来判断
                    }
                }
                break;
        }
        return super.dispatchTouchEvent(ev);
    }
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        Logger.log("CustomScrollView onInterceptTouchEvent "   ev.getAction());
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mDownY = ev.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                float dis = ev.getRawY() - mDownY;
                if (dis < 0 && Math.abs(dis) >= mSlop) {
                    //当触摸事件是向上滑动并且滑动距离超过屏幕的最小滑动单位时，不拦截滑动事件
                    //这里的目的是取消dispatchTouchEvent中对该事件系列的拦截，当scroller view不需要拦截时，
                    //会执行到这里，
                    return false;
                }
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }