遇到的问题描述：

嵌套后ViewPager中的view展示不出来，解决办法：重新设置Viewpager的高度

自定义viewpager

public class WrapViewPager extends ViewPager {

    private int current;
    private int height = 0;
    /**
     * 保存position与对于的View
     */
    private HashMap<Integer, View> childrenViews = new LinkedHashMap();

    private boolean isCanScroll = false;

    public WrapViewPager(Context context) {
        super(context, null);
    }

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

    public void setScanScroll(boolean isCanScroll) {
        this.isCanScroll = isCanScroll;
    }//切换tab的时候重新设置viewpager的高度
    public void resetHeight(int current) {
        this.current = current;
        if (childrenViews.size() > current) {
            LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) getLayoutParams();
            if (layoutParams == null) {
                layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, height);
            } else {
                layoutParams.height = height;
            }
            setLayoutParams(layoutParams);
        }
    }

    /**
     * 保存position与对于的View
     */
    public void setObjectForPosition(View view, int position) {
        childrenViews.put(position, view);
    }

    @Override
    public void scrollTo(int x, int y) {
        super.scrollTo(x, y);
    }

    @Override
    public boolean onTouchEvent(MotionEvent arg0) {
        try {
            if (isCanScroll) {
                return super.onTouchEvent(arg0);
            }
        } catch (Exception e) {
        }

        return false;

    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent arg0) {
        try {
            if (isCanScroll) {
                return super.onInterceptTouchEvent(arg0);
            }
        } catch (Exception e) {

        }

        return false;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        if (childrenViews.size() > current) {
            View child = childrenViews.get(current);
            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            height = child.getMeasuredHeight();
        }
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}

　　调用的方法：创建三个自定义view，添加到view列表中

view1 = UserView(context)
        viewpager.setObjectForPosition(goodView,0)
        view2  = UserView(context)
        viewpager.setObjectForPosition(middleView,1)
        view3 = UserView(context)
        viewpager.setObjectForPosition(badView,2)

pageList.add(view1)       pageList.add(view2)       pageList.add(view3)

监听viewpager

 viewpager.addOnPageChangeListener(object : ViewPager.OnPageChangeListener {
            override fun onPageScrollStateChanged(p0: Int) {
            }

            override fun onPageScrolled(p0: Int, p1: Float, p2: Int) {
            }

            override fun onPageSelected(index: Int) {
                viewpager.resetHeight(index)
                //自己的代码实现
            }
        })

设置好后高度问题解决了，因自定义view为了防止tab切换时每次重新加载页面和数据，做了return处理，这里viewpager高度变化后，

NestedScrollView 的高度也许变化，监听是否到底部的事件得重新监听，放到return之前即可

scrollView.setOnScrollChangeListener(NestedScrollView.OnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
            if (scrollY == v.getChildAt(0).measuredHeight - v.measuredHeight) {
                //到底了
                if (isLoadMore) {
                    
                } else {
                   
                }
            }
        })

if (isLoading) {    return}