ScrollView嵌套ListView，.measure(0,0);空指针NullException

First: SrollView嵌套ListView时显示不全问题及ListView高度问题：直接上代码，使用以下函数解决此问题：

    public void setListViewHeightOnChildren(ListView listView) {        //adapter为ListView的适配器        if (adapter == null) {            return;        }        int totalHeight = 0;        for (int i = 0, len = adapter.getCount(); i < len; i++) {            // 返回数据项的数目            View listItem = adapter.getView(i, null, listView);            // 子项View 的宽高            listItem.measure(0, 0);            // 计算所有子项的总高度            totalHeight += listItem.getMeasuredHeight();        }        ViewGroup.LayoutParams params = listView.getLayoutParams();        // 获取子项间分隔符占用的高度，adapter.getCount() == 1 ? 2 : adapter.getCount() - 1这个判断是为了解决特殊情况(比如Item有设置MarginTop....)，当只有一个Item时滑动出现显示不全及被截取一部分问题；        params.height = totalHeight                + (listView.getDividerHeight() * (adapter.getCount() == 1 ? 2                        : adapter.getCount() - 1));        listView.setLayoutParams(params);    }

Two: 当调用listItem.measure(0, 0);报空指针时问题:检查Adapter适配时Item的根容器为RelativeLayout,报错原因：In platform version 17 and lower, RelativeLayout was affected by a measurement bug that could cause child views to be measured with incorrect MeasureSpec values. (See MeasureSpec.makeMeasureSpec for more details.) This was triggered when a RelativeLayout container was placed in a scrolling container, such as a ScrollView or HorizontalScrollView. If a custom view not equipped to properly measure with the MeasureSpec mode UNSPECIFIED was placed in a RelativeLayout, this would silently work anyway as RelativeLayout would pass a very large AT_MOST MeasureSpec instead.This behavior has been preserved for apps that set android:targetSdkVersion="17" or older in their manifest's uses-sdktag for compatibility. Apps targeting SDK version 18 or newer will receive the correct behavior有三种解决方案：一、升级版本到4.2.2二、更改根容器为LinearLayout三、在适配器里添加convertView.setLayoutParams(new LayoutParams(                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); convertView为Item的view