【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。