使用Volley框架异步加载图片+ListView图片加载错位解决

上面使用AsyncTask异步加载图片,这里使用Volley框架，图片的缓存不需要自己去处理。

BitmapCache类：

package com.dystudio.ustc.asyncimageloader_listview_volley;

import android.graphics.Bitmap;
import android.support.v4.util.LruCache;
import android.util.Log;

import com.android.volley.toolbox.ImageLoader.ImageCache;


public class BitmapCache implements ImageCache {

	private static final String TAG = "BitmapCache";
	private LruCache mCache;

	public BitmapCache() {

		int maxSize = 4 * 1024 * 1024;

		mCache = new LruCache(maxSize) {
			@Override
			protected int sizeOf(String key, Bitmap bitmap) {

				return bitmap.getRowBytes() * bitmap.getHeight();
			}

		};

	}

	@Override
	public Bitmap getBitmap(String url) {

		Log.i(TAG, "get cache " + url);

		return mCache.get(url);
	}

	@Override
	public void putBitmap(String url, Bitmap bitmap) {
		Log.i(TAG, "get cache: " + url);
		if (bitmap != null) {

			mCache.put(url, bitmap);

		}

	}

}

MyAdapter:

package com.dystudio.ustc.asyncimageloader_listview_volley;

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

import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
import com.android.volley.toolbox.Volley;



public class MyAdapter extends BaseAdapter {

	private String[] list;

	private Context context;

	private RequestQueue queue;

	private ImageLoader imageLoader;

	public MyAdapter(Context context, String[] list) {

		this.context = context;

		this.list = list;

		queue = Volley.newRequestQueue(context);

		imageLoader = new ImageLoader(queue, new BitmapCache());
	}

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

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

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

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {

		ViewHolder holder = null;

		if (convertView == null) {

			holder = new ViewHolder();

			convertView = LayoutInflater.from(context).inflate(
					R.layout.list_item, null);
			holder.img = (NetworkImageView) convertView
					.findViewById(R.id.userimage);

			convertView.setTag(holder);

		} else {

			holder = (ViewHolder) convertView.getTag();

		}
		String imgUrl = list[position];

		if (imgUrl != null && !imgUrl.equals("")) {

			holder.img.setDefaultImageResId(R.drawable.ic_launcher);
			holder.img.setErrorImageResId(R.drawable.ic_launcher);
			holder.img.setImageUrl(imgUrl, imageLoader);

		}

		return convertView;
	}

	static class ViewHolder {
		NetworkImageView img;
	}

}

MainActivity:

package com.dystudio.ustc.asyncimageloader_listview_volley;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

public class MainActivity extends Activity {
	ListView listView;
	String[] images = new String[] {
			"https://img-my.csdn.net/uploads/201407/26/1406383299_1976.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383291_6518.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383291_8239.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383290_9329.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383290_1042.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383275_3977.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383265_8550.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383264_3954.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383264_4787.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383264_8243.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383248_3693.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383243_5120.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383242_3127.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383242_9576.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383242_1721.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383219_5806.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383214_7794.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383213_4418.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383213_3557.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383210_8779.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383172_4577.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383166_3407.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383166_2224.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383166_7301.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383165_7197.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383150_8410.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383131_3736.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383130_5094.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383130_7393.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383129_8813.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383100_3554.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383093_7894.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383092_2432.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383092_3071.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383091_3119.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383059_6589.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383059_8814.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383059_2237.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383058_4330.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406383038_3602.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382942_3079.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382942_8125.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382942_4881.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382941_4559.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382941_3845.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382924_8955.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382923_2141.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382923_8437.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382922_6166.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382922_4843.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382905_5804.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382904_3362.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382904_2312.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382904_4960.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382900_2418.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382881_4490.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382881_5935.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382880_3865.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382880_4662.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382879_2553.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382862_5375.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382862_1748.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382861_7618.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382861_8606.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382861_8949.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382841_9821.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382840_6603.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382840_2405.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382840_6354.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382839_5779.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382810_7578.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382810_2436.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382809_3883.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382809_6269.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382808_4179.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382790_8326.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382789_7174.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382789_5170.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382789_4118.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382788_9532.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382767_3184.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382767_4772.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382766_4924.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382766_5762.jpg",
			"https://img-my.csdn.net/uploads/201407/26/1406382765_7341.jpg"};

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		listView = (ListView) findViewById(R.id.listview);
		MyAdapter adapter = new MyAdapter(this, images);
		listView.setAdapter(adapter);
	}
}