viewPager使用时加载数据时显示IllegalStateException异常，解决不了。。。。

从newsPager中得到newsDetailTitles标题的详细内容，这是通过构造器传过来的。打印日志78行能打印，45行打印出来共size是12.但是程序出现了异常
java.lang.IllegalStateException: 
The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged。

从网上查询的结果是adapter中的数据改变了，却没有重新加载数据，需要在数据改变之后adapter.notifyDataSetChanged。但是找不到数据改变的地方。
今天太累了，这个bug找到答案时再写。

 1 package com.atguigu.beijingnews2.pager.newsdetailpager;

import android.app.Activity;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.atguigu.beijingnews2.R;
import com.atguigu.beijingnews2.utils.LogUtils;

import org.xutils.view.annotation.ViewInject;
import org.xutils.x;

import java.util.ArrayList;

/**
 * Created by Administrator on 2016/2/18.
 */
public class NewsDetailPager {
    private Activity activity;
    @ViewInject(R.id.vp_news_detail_paper)
    private ViewPager vp_news_detail_paper;
    private ArrayList<String> newsDetailTitles=new ArrayList<>() ;
    private PagerAdapter adapter = new PagerAdapter() {
        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            LogUtils.e("TAG");
//            String title = newsDetailTitles.get(position);
//            textView.setText(title);
            container.addView(views.get(position));
            return views.get(position);
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            LogUtils.e("TAG");
            container.removeView((View) object);
        }

        @Override
        public int getCount() {
            LogUtils.e("TAG" + newsDetailTitles.size());

            return newsDetailTitles.size();
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            LogUtils.e("TAG");
            return view == object;
        }
    };
    private TextView textView;
    ArrayList<View> views = new ArrayList<>();
    public NewsDetailPager(Context context, ArrayList<String> newsDetailTitles ) {
        activity = (Activity) context;
        this.newsDetailTitles=newsDetailTitles;
//        initView();


    }



    public View initView() {
        View view = View.inflate(activity, R.layout.news_detail_paper, null);
        x.view().inject(this, view);
        for (int i = 0; i < newsDetailTitles.size(); i++) {
            TextView textView = new TextView(activity);
            textView.setText(newsDetailTitles.get(i));
            views.add(textView);
            LogUtils.e("TAG");
        }
//        textView = new TextView(activity);
        LogUtils.e("TAG");
        vp_news_detail_paper.setAdapter(adapter);
        return view;
    }
}

E/AndroidRuntime: FATAL EXCEPTION: main
                                                                        Process: com.atguigu.beijingnews2, PID: 1622
                                                                        java.lang.IllegalStateException: The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged! Expected adapter item count: 0, found: 4 Pager id: com.atguigu.beijingnews2:id/vp_news_pager Pager class: class com.atguigu.beijingnews2.view.NoScrollViewPager Problematic adapter: class com.atguigu.beijingnews2.pager.NewsPager$2
                                                                            at android.support.v4.view.ViewPager.populate(ViewPager.java:999)
                                                                            at android.support.v4.view.ViewPager.populate(ViewPager.java:951)
                                                                            at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1473)
                                                                            at android.view.View.measure(View.java:16497)
                                                                            at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
                                                                            at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
                                                                            at android.view.View.measure(View.java:16497)
                                                                            at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1488)
                                                                            at android.view.View.measure(View.java:16497)
                                                                            at android.widget.LinearLayout.measureVertical(LinearLayout.java:847)
                                                                            at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
                                                                            at android.view.View.measure(View.java:16497)
                                                                            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
                                                                            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                                                                            at android.view.View.measure(View.java:16497)
                                                                            at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
                                                                            at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
                                                                            at android.view.View.measure(View.java:16497)