网络获取图片（缓存）

package com.hsx.imageloader.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.hsx.imageloader.listener.AnimateFirstDisplayListener;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.assist.ImageLoadingListener;
import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer;
import com.hsx.imageloader.R;

public class ItemAdapter extends BaseAdapter {
DisplayImageOptions options;

private ImageLoadingListener animateFirstListener = new AnimateFirstDisplayListener();

String[] imageUrls;
Context context;

public ItemAdapter(String[] imageUrls, Context context) {
super();
this.imageUrls = imageUrls;
this.context = context;
options = new DisplayImageOptions.Builder()
.showStubImage(R.drawable.ic_launcher)//设置图片在下载期间显示的图片
.showImageForEmptyUri(R.drawable.ic_launcher)//设置图片Uri为空或是错误的时候显示的图片
.showImageOnFail(R.drawable.ic_launcher)//设置图片加载/解码过程中错误时候显示的图片
.cacheInMemory(true)//是否緩存都內存中
.cacheOnDisc(true)//是否緩存到sd卡上
.displayer(new RoundedBitmapDisplayer(20))
.build();
}

private class ViewHolder {
public TextView text;
public ImageView image;
}

@Override
public int getCount() {
return imageUrls.length;
}

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

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

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.item_list_image, parent, false);
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.text);
holder.image = (ImageView) convertView.findViewById(R.id.image);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}

holder.text.setText("Item " (position 1));
// ImageLoader
ImageLoader imageLoader = ImageLoader.getInstance();
imageLoader.displayImage(imageUrls[position], holder.image, options, animateFirstListener);

return convertView;
}
}