/**  * User: Tom  * Date: 13-5-13  * Time: 下午8:07  */ public class AsnycImageLoader {     //定义一个HashMap进行存放缓存的Image key为String Value为一个弱引用的一个资源文件     // 图片 为了方便JAVA的回收     private Map<String, SoftReference<Drawable>> imageCache = null;     public AsnycImageLoader() {         imageCache = new HashMap<String, SoftReference<Drawable>>();     }     /**      * 加载图片      * <p>imageurl为下载资源的URL，      * ImageCallback当缓存中不存在相关图片时时行网络下载      * 在多线程下要使用Handler进行操作UI 利用回调接口的方式进行更新UI      * </p>      * @param imageUrl      * @param callback      * @return      */     public Drawable loadDrawable(final String imageUrl, final ImageCallback callback) {         //进行判断ImageCache中是否存在缓存图片         if (imageCache.containsKey(imageUrl)) {             SoftReference<Drawable> softReference = imageCache.get(imageUrl);             if (softReference.get() != null) {                 return softReference.get();             }         }         //定义操作UI的Handler         final Handler handler = new Handler() {             @Override             public void handleMessage(Message msg) {                 callback.imageLoaded((Drawable) msg.obj);             }         };         new Thread(new Runnable() {             @Override             public void run() {                 Drawable drawable = loadImageFromUrl(imageUrl);                 imageCache.put(imageUrl, new SoftReference<Drawable>(drawable));                 Message message = handler.obtainMessage(0, drawable);                 handler.sendMessage(message);             }         }).start();         return null;     }     //根据URL地址进行获取资源     protected Drawable loadImageFromUrl(String imageUrl) {         try {             return Drawable.createFromStream(new URL(imageUrl).openStream(), "src");         } catch (Exception e) {             throw new RuntimeException();         }     }     //回调接口     public interface ImageCallback {         public abstract void imageLoaded(Drawable drawable);     } }

/**  * User: Tom  * Date: 13-5-13  * Time: 下午8:33  */ public class LoadImage extends Activity {     private AsnycImageLoader loader = null;     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.loadimages);         loader = new AsnycImageLoader();         loadImage("http://www.1sucai.cn/images/icon-partners.png", R.id.image1);         loadImage("http://www.1sucai.cn/images/icon-dev.png", R.id.image2);         loadImage("http://pic28.jb51.net/20130421/12302174_231210305323_2.jpg", R.id.image3);     }     public void loadImage(String url, int id) {         final ImageView imageView = (ImageView) findViewById(id);         Drawable cacheImage = loader.loadDrawable(url, new AsnycImageLoader.ImageCallback() {             @Override             public void imageLoaded(Drawable drawable) {                 imageView.setImageDrawable(drawable);             }         });         if (cacheImage != null) {             imageView.setImageDrawable(cacheImage);         }     } }