AsyncImageLoader.java

  import java.io.InputStream;  import java.lang.ref.SoftReference;  import java.net.URL;  import java.util.HashMap;    import android.graphics.drawable.Drawable;  import android.os.Handler;  import android.os.Message;  import android.widget.ImageView;  /**   * 实现图片的异步载入显示   * @author kandanle   *   */  public class AsyncImageLoader {        /**       * 软引用对象，在响应内存需要时，由垃圾回收器决定是否清除此对象。软引用对象最常用于实现内存敏感的缓存。       */      private HashMap<String, SoftReference<Drawable>> imageCache;        public AsyncImageLoader(){          imageCache = new HashMap<String, SoftReference<Drawable>>();      }        public Drawable loadDrawable(final String imageUrl,final ImageView imageView,final ImageCallback imagecallback){          if(imageCache.containsKey(imageUrl)){              //从缓存中读取人人              SoftReference<Drawable> softReference = imageCache.get(imageUrl);              Drawable drawable = softReference.get();              if(drawable != null){                  return drawable;              }          }          final Handler handler = new Handler(){              @Override              public void handleMessage(Message msg) {                  super.handleMessage(msg);                  imagecallback.imageLoaded((Drawable)msg.obj, imageView, imageUrl);              }          };          new Thread(){              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;      }        public static Drawable loadImageFromUrl(String urlPath){          URL url;          InputStream is = null;          try{              url = new URL(urlPath);              is = (InputStream)url.getContent();          }catch(Exception e){              e.printStackTrace();          }          Drawable drawable = Drawable.createFromStream(is, "src");          return drawable;      }    }

ImageCallback.java

import android.graphics.drawable.Drawable;  import android.widget.ImageView;    public interface ImageCallback {      public void imageLoaded(Drawable imageDrawable,ImageView imageView, String imageUrl);  }    Drawable drawable = asyncImageLoader.loadDrawable(weiboInfo.getUserIcon(), viewUserIcon, new ImageCallback() {      @Override      public void imageLoaded(Drawable imageDrawable, ImageView imageView,String imageUrl) {      imageView.setImageDrawable(imageDrawable);          }  });  if(drawable == null){      viewUserIcon.setImageResource(R.drawable.portrait);  }else{      viewUserIcon.setImageDrawable(drawable);  }