android實現ListView嵌套ListView時，滑動到底部程序會停止的問題

主要是要注意在父ListView的適配器裏判斷子ListView的position是否爲空，如果爲空則不加載

        if(crimes.get(position)!=null)
        {
            holder.txtshow.setAdapter(new CarMessgeAdapter(crimes.get(position)));
        }

完整的適配器代碼

package com.example.tangweilong.demo;

import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
/**
 * Created by liying on 2016/11/20.
 */
public class MyAdap extends BaseAdapter {


    private ArrayList<Friend> friends;
    private ArrayList<Crime> crimes;
    public MyAdap(ArrayList<Friend> friends,ArrayList<Crime> crimes) {
        this.friends = friends;
        this.crimes = crimes;
    }

    @Override
    public int getCount() {
        return friends.size();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        View view = convertView;
        if (view == null) {
            view = View.inflate(parent.getContext(), R.layout.activity_testlist, null);
            holder = new ViewHolder();
            holder.tv_first = (TextView) view.findViewById(R.id.tv_first);
            holder.txtshow = (ListView) view.findViewById(R.id.txtshow);
            view.setTag(holder);
        } else {
            holder = (ViewHolder) view.getTag();
        }
        String pinpai=null;
        //如果爲空則不加載，否則程序會停止
        if(crimes.get(position)!=null)
        {
            pinpai=crimes.get(position).getmBrand();
            holder.txtshow.setAdapter(new CarMessgeAdapter(crimes.get(position)));
        }


        String firstChar = friends.get(position).pinyin.charAt(0) + "   "+pinpai;
        if (position > 0) {
            String lastChar = friends.get(position - 1).pinyin.charAt(0) + "";
            if (firstChar.equalsIgnoreCase(lastChar)) {
                holder.tv_first.setVisibility(View.GONE);
            } else {
                holder.tv_first.setVisibility(View.VISIBLE);
                holder.tv_first.setText(firstChar);
            }
        } else {
            holder.tv_first.setVisibility(View.VISIBLE);
            holder.tv_first.setText(firstChar);
        }
        Log.w("滑動事件：", "位置"+position);



        return view;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    static class ViewHolder {
        private TextView tv_first;
        private ListView txtshow;

    }

}