ListAdapter listAdapter = listView.getAdapter();
    if (listAdapter == null) {

        return;
    }

    int totalHeight = 0;
    for (int i = 0, len = listAdapter.getCount(); i < len; i++) {   //listAdapter.getCount()返回数据项的数目
        View listItem = listAdapter.getView(i, null, listView);
        listItem.measure(0, 0);  //计算子项View 的宽高
        totalHeight += listItem.getMeasuredHeight();  //统计所有子项的总高度
    }
    ViewGroup.LayoutParams params = listView.getLayoutParams();
    // listView.getpiderHeight()获取子项间分隔符占用的高度
    int piderHeight = (listView.getpiderHeight() * (listAdapter.getCount() - 1));
    // params.height最后得到整个ListView完整显示需要的高度:item总和 +  分割线总和高度
    params.height = totalHeight + piderHeight;

    listView.setLayoutParams(params);