我在检索albumArt时遇到问题,并在游标适配器中使用AsyncTask将该艺术设置为ImageView。 当我打开我的应用程序时,它看起来像这样:
然后我向下滚动列表,一切都很好(但如果我滚动列表不是很快):
我想我可能做错了,所以我有疑问:
有可能以某种方式解决这个问题,我已经尝试了很多不同的方法来实现AsyncTask并使其工作正常,但在一天结束时看起来总是一样。
下面是游标适配器的代码:
public class AllSongsCursorAdapter extends CursorAdapter {
public AllSongsCursorAdapter(Context context, Cursor cursor) {
super(context, cursor, 0);
}
public boolean isCheckBoxVisible;
private AddToFavouritesArray favouritesArray = AddToFavouritesArray.getInstance();
private static class ViewHolder {
CheckBox checkBox;
TextView title;
TextView artist;
ImageView albumArt;
private ViewHolder(View view) {
checkBox = (CheckBox) view.findViewById(R.id.favouritesCheckBox);
title = (TextView) view.findViewById(R.id.title);
artist = (TextView) view.findViewById(R.id.artist);
albumArt = (ImageView) view.findViewById(R.id.albumArt);
}
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
View view = LayoutInflater.from(context).inflate(R.layout.song_item, viewGroup, false);
ViewHolder viewHolder = new ViewHolder(view);
view.setTag(viewHolder);
return view;
}
@Override
public void bindView(View view, Context context, final Cursor cursor) {
final ViewHolder viewHolder = (ViewHolder) view.getTag();
if (isCheckBoxVisible) {
viewHolder.checkBox.setVisibility(View.VISIBLE);
} else {
viewHolder.checkBox.setVisibility(View.GONE);
}
final int position = cursor.getPosition();
viewHolder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
if (b) {
favouritesArray.integerArray.add(position);
} else {
favouritesArray.integerArray.remove(Integer.valueOf(position));
}
}
});
int songTitle = cursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
int songArtist = cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
String currentTitle = cursor.getString(songTitle);
String currentArtist = cursor.getString(songArtist);
viewHolder.title.setText(currentTitle);
viewHolder.artist.setText(currentArtist);
//__________________________ALBUM_ART_______________________________________________________
viewHolder.albumArt.setTag(cursor.getPosition());
new AsyncTask<ViewHolder, Void, Bitmap>(){
private ViewHolder viewHolder;
@Override
protected Bitmap doInBackground(ViewHolder... viewHolders) {
viewHolder = viewHolders[0];
int id = cursor.getColumnIndex(MediaStore.Audio.Media._ID);
long songId = cursor.getLong(id);
Bitmap albumArt = getAlbumId(context, songId);
return albumArt;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
super.onPostExecute(bitmap);
if(bitmap != null) {
viewHolder.albumArt.setImageBitmap(bitmap);
}else{
viewHolder.albumArt.setImageResource(R.drawable.placeholder);
}
}
}.execute(viewHolder);
}
private Bitmap getAlbumId(Context context, long id) {
Bitmap albumArt = null;
String selection = MediaStore.Audio.Media._ID + " = " + id + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, new String[]{
MediaStore.Audio.Media._ID, MediaStore.Audio.Media.ALBUM_ID},
selection, null, null);
if (cursor.moveToFirst()) {
long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
albumArt = getAlbumArt(context, albumId);
}
cursor.close();
return albumArt;
}
private Bitmap getAlbumArt(Context context, long albumId) {
Bitmap albumArt = null;
String selection = MediaStore.Audio.Albums._ID + " = " + albumId + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI, null, selection, null, null);
if (cursor.moveToFirst()) {
int art = cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART);
String currentArt = cursor.getString(art);
albumArt = BitmapFactory.decodeFile(currentArt);
}
cursor.close();
return albumArt;
}
}
是的,当然,没有AsyncTask一切正常,但滚动速度很慢。 提前谢谢!
修改
在一天结束时,这就是它的工作原理。非常感谢@Orest Savchak,我的投票和接受你的回答。非常感谢。 // __________________________ ALBUM_ART _______________________________________________________
int id = cursor.getColumnIndex(MediaStore.Audio.Media._ID);
long songId = cursor.getLong(id);
String string = getAlbumArtPath(context, songId);
if(string!=null) {
Picasso.with(context)
.load(new File(string))
.into(viewHolder.albumArt);
}else{
viewHolder.albumArt.setImageResource(R.drawable.placeholder);
}
}
private String getAlbumArtPath(Context context, long id) {
String selection = MediaStore.Audio.Media._ID + " = " + id + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, new String[]{
MediaStore.Audio.Media._ID, MediaStore.Audio.Media.ALBUM_ID},
selection, null, null);
if (cursor.moveToFirst()) {
long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
return getAlbumArt(context, albumId);
}
cursor.close();
return null;
}
private String getAlbumArt(Context context, long albumId) {
String selection = MediaStore.Audio.Albums._ID + " = " + albumId + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI, null, selection, null, null);
if (cursor.moveToFirst()) {
int art = cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART);
return cursor.getString(art);
}
cursor.close();
return null;
}
答案 0 :(得分:2)
您应该自己管理自己的任务。您的视图已被回收,因此,您有一个不同行的视图,这会导致问题。大多数项目使用一些库,它们会自动为您完成 - 更容易,例如Picasso
Picasso.with(context).load(new File(getAlbumArtPath(context, songId))).into(viewHolder.albumArt);
private String getAlbumArtPath(Context context, long id) {
String selection = MediaStore.Audio.Media._ID + " = " + id + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, new String[]{
MediaStore.Audio.Media._ID, MediaStore.Audio.Media.ALBUM_ID},
selection, null, null);
if (cursor.moveToFirst()) {
long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
return getAlbumArt(context, albumId);
}
cursor.close();
return null;
}
private String getAlbumArt(Context context, long albumId) {
String selection = MediaStore.Audio.Albums._ID + " = " + albumId + "";
Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI, null, selection, null, null);
if (cursor.moveToFirst()) {
int art = cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART);
return cursor.getString(art);
}
cursor.close();
return null;
}