android - PagerAdapter中destroyItem遇到IndexOutOfBoundsException

Question

写了一个无限循环的ViewPager，原理是在最左和最右各增加一个View，用于滑动。但是跑Monkey的时候爆出：

CRASH: com.wzy.test(pid 11400)
// Short Msg: java.lang.IndexOutOfBoundsException保存 
// Long Msg: java.lang.IndexOutOfBoundsException: Invalid index 3, size is 3
// Build Changelist: 1475158271
// Build Time: 1475158954000
// java.lang.IndexOutOfBoundsException: Invalid index 3, size is 3
//     at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:260)
//     at java.util.ArrayList.get(ArrayList.java:313)
//     at com.wzy.test.widget.MarqueeContainer$MarqueePagerAdapter.destroyItem(MarqueeContainer.java:230)
//     at android.support.v4.view.ViewPager.setAdapter(ViewPager.java:474)
//     at com.wzy.test.widget.MarqueeContainer.showMarquee(MarqueeContainer.java:169)
//     at com.wzy.test.widget.MarqueeContainer.setImagesUrl(MarqueeContainer.java:76)
//     at com.wzy.test.activity.DetailActivity$1.handleMessage(DetailActivity.java:62)
//     at android.os.Handler.dispatchMessage(Handler.java:111)
//     at android.os.Looper.loop(Looper.java:205)
//     at android.app.ActivityThread.main(ActivityThread.java:5811)
//     at java.lang.reflect.Method.invoke(Native Method)
//     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:806)
//     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)

很奇怪，理论上一共就有三个item，destoryItem的position不应该为3.

实现的PagerAdapter：

public class MarqueePagerAdapter extends PagerAdapter {

    /**
     * 获取要滑动控件的数量.我们的自定义控件用来实现图片的滑动,因此这里就应该是展示的图片的数量.
     */
    @Override
    public int getCount() {
        return mDisplayViewList == null ? 0 : mDisplayViewList.size();
    }

    /**
     * 来判断显示的是否是同一张图片,我们直接将两个参数进行比较即可.
     */
    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    /**
     * 当要显示的图片可以进行缓存的时候,会调用这个方法进行显示图片的初始化.
     * 我们将要显示的ImageView添加到container中,然后将该ImageView返回即可.
     */
    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(mDisplayViewList.get(position));
        return mDisplayViewList.get(position);
    }

    /**
     * ViewPager默认只缓存三张要显示的图片,如果滑动的图片超过了缓存的范围,就会调用这个方法将图片移除
     */
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(mDisplayViewList.get(position));
    }
}

求指导一下，大家是怎么解决这个问题的？（ps：没有调用过notifyDataSetChanged方法）。

Answer 1

The problem is that the array is out of bounds
Make a log in the destroyItem method to see the actual data num of mDisplayViewList.size(). I guess your mDisplayViewList data has changed elsewhere in the code. In addition, what is the specific data of mDisplayViewList?
Solution provided Reference

@Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        if(position > mDisplayViewList.size() - 1)return;
        container.removeView(mDisplayViewList.get(position));
    }