我有一个从服务器相册加载图像的galleyview。但我的相册有很多图片 [超过 500 张]。所以一旦我更快地滚动galleyview，后台任务的数量就会越来越多，所以应用程序会崩溃。所以我打算根据galleyview中的位置杀死[取消]一些旧任务。所以请提出一些解决方案。下面提供了源代码。
任务调用：
DownloadImageTask downloadTask = new DownloadImageTask(
ShowGallery.this, view,position);
// cancel some task to avoid the crash - need to implement
// cancelPotentialDownload(position);
downloadTask.execute( THUMB_PREFIX + picture.getFileName(),
picture.getForceExtension(), thumbUrl,albumName, bitmapsCache, position, picture,null);
private static boolean cancelPotentialDownload(int position) {
// need to implement.
}
下载图片任务
public class DownloadImageTask extends AsyncTask<Object, Void, Bitmap> {
Context activity;
private ImageView view;
public int position;
public DownloadImageTask(Context context, ImageView imageView, int imagePosition) {
super();
activity = context;
view = imageView;
position = imagePosition;
}
@Override
protected Bitmap doInBackground(Object... parameters) {
String fileName = (String) parameters[0];
String extension = (String) parameters[1];
String thumbUrl = (String) parameters[2];
Integer currentAlbumName = (Integer) parameters[3];
Map<Integer, Bitmap> bitmapsCache = (Map<Integer, Bitmap>) parameters[4];
Integer position = (Integer) parameters[5];
Picture picture = (Picture) parameters[6];
Album album = (Album) parameters[7];
Bitmap downloadImage = null;
File imageFileOnExternalDirectory = null;
try {
imageFileOnExternalDirectory = FileUtils.getInstance()
.getFileFromGallery(activity, fileName, extension,
thumbUrl, true, currentAlbumName);
downloadImage = BitmapFactory
.decodeFile(imageFileOnExternalDirectory.getPath());
if (picture != null) {
// only for showgallery activity
picture.setThumbImageCachePath(imageFileOnExternalDirectory
.getPath());
bitmapsCache.put(position, downloadImage);
} else if (album != null) {
// only for albumadapter
album.setAlbumCoverCachePath(imageFileOnExternalDirectory
.getPath());
}
} catch (GalleryConnectionException e) {
// Log.v(TAG, e.getMessage());
} catch (FileHandlingException e) {
// Log.v(TAG, e.getMessage());
}
return downloadImage;
}
@Override
protected void onPostExecute(Bitmap downloadImage) {
if (downloadImage != null) {
view.setImageBitmap(downloadImage);
}
}
}