【项目笔记】【bug】数组空指针异常

package com.example.googleplay.ui.holder;

import java.util.ArrayList;

import android.view.View;
import android.widget.ImageView;

import com.example.googleplay.R;
import com.example.googleplay.http.HttpHelper;
import com.example.googleplay.utils.BitmapHelper;
import com.example.googleplay.utils.UIUtils;
import com.lidroid.xutils.BitmapUtils;

public class HomeScreenHolder extends BaseHolder<ArrayList<String>> {

    private ImageView[] mImages = null;
    private BitmapUtils mBitmapUtils;

    @Override
    public View initView() {
        View view = UIUtils.inflate(R.layout.layout_detail_picinfo);

        mImages = new ImageView[5];
        mImages[0] = (ImageView) view.findViewById(R.id.iv_pic1);
        mImages[1] = (ImageView) view.findViewById(R.id.iv_pic2);
        mImages[2] = (ImageView) view.findViewById(R.id.iv_pic3);
        mImages[3] = (ImageView) view.findViewById(R.id.iv_pic4);
        mImages[4] = (ImageView) view.findViewById(R.id.iv_pic5);
        
        mBitmapUtils = BitmapHelper.getBitmapUtils();
        return view;
    }

    @Override
    public void refreshView(ArrayList<String> data) {
        
        for (int i = 0; i < mImages.length; i++) {
            if(i>=data.size()){
                //多余的图片布局需要隐藏
                mImages[i].setVisibility(View.GONE);
            }else {
                //要显示的图片
                mImages[i].setVisibility(View.VISIBLE);
                mBitmapUtils.display(mImages[i], HttpHelper.URL + "image?name=" + data.get(i));
            }
        }
    }
}

在refreshView这个方法中mImages报空指针异常，其实是第16行的原因，数组赋值只能一次赋值，赋值之后再赋值无效，应该写成

     private ImageView[] mImages;

但是可以给数组的每个元素再次赋值。