Android多线程下载远程图片

修改后的代码

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import java.io.InputStream; import java.lang.ref.WeakReference; import java.net.HttpURLConnection; import java.net.URL; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.AsyncTask; import android.util.Log; import android.widget.ImageView; /**  * @类名：ImageDownloader  * @功能描述：优化的ImageDownloader, 不带缓存，在线下载，用户头像请使用。  * @作者： William Xu  * @创建日期：2013-6-7  * @修改人：  * @修改日期：  * @修改备注：  * @版本号：1.0  */ public class ImageDownloader {     public void download(String url, ImageView imageView) {         BitmapDownloaderTask task = new BitmapDownloaderTask(imageView);         task.execute(url);     }     class BitmapDownloaderTask extends AsyncTask<String, Void, Bitmap> {                     private final WeakReference<ImageView> imageViewReference; // 使用WeakReference解决内存问题         public BitmapDownloaderTask(ImageView imageView) {             imageViewReference = new WeakReference<ImageView>(imageView);         }         @Override         protected Bitmap doInString...  params) { // 实际的下载线程，内部其实是concurrent线程，所以不会阻塞             Bitmap bitmap = null;             try {                 URL imageUrl = new URL(params[0]);                 HttpURLConnection conn = (HttpURLConnection) imageUrl                         .openConnection();                 conn.setConnectTimeout(30000);                 conn.setReadTimeout(30000);                 conn.setInstanceFollowRedirects(true);                 InputStream is = conn.getInputStream();                 bitmap = BitmapFactory.decodeStream(is);             } catch (Exception ex) {                 Log.e("",                         "getBitmap catch Exception...\nmessage = "                                 + ex.getMessage());             }             return bitmap;         }         @Override         protected void onPostExecute(Bitmap bitmap) { // 下载完后执行的             if (isCancelled()) {                 bitmap = null;             }             if (imageViewReference != null) {                                     ImageView imageView = imageViewReference.get();                                     if (imageView != null && bitmap != null) {                                             imageView.setImageBitmap(bitmap); // 下载完设置imageview为刚才下载的bitmap对象                 }             }         }     } }

本文转自william_xu 51CTO博客，原文链接：http://blog.51cto.com/williamx/1218518，如需转载请自行联系原作者