我正在创建一个使用RecyclerView显示sd卡文件的应用程序，我还添加了一个删除文件的按钮。但问题是RecyclerView被删除但原始文件没有删除。任何帮助将不胜感激。
OnClick删除按钮的代码：
holder.deleteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File file = new File(String.valueOf(trackuri));
file.delete();
mMusic.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position,mMusic.size());
Toast.makeText(mContext,"Removed : " , Toast.LENGTH_SHORT).show();
}
});
完整类适配器的代码：
public MusicAdapter(Context context, List<Music> music) {
mMusic = new ArrayList<>();
if(music != null) {
mMusic.addAll(music);
}
mContext = context;
mPlaceholder = (BitmapDrawable) mContext.getResources().getDrawable(R.drawable.ic_music_note_black_48dp);
// Get the maximum size of byte we are allowed to allocate on the VM head and convert it to bytes.
int maxSize = (int) (Runtime.getRuntime().maxMemory() / 1024);
// Divide the maximum size by eight to get a adequate size the LRU cache should reach before it starts to evict bitmaps.
int cacheSize = maxSize / 8;
mBitmapCache = new LruCache<Long, Bitmap>(cacheSize) {
@Override
protected int sizeOf(Long key, Bitmap value) {
// returns the size of bitmaps in kilobytes.
return value.getByteCount() / 1024;
}
};
}
/**
* Adds a {@link Music} item to the Adapter.
* @param
*/
/**
* Adds a {@link List} of {@link Music} to the adapters.
* This method replaces the current music items inside of the adapter with the specified music items.
* @param
*/
public void clearItem() {
mMusic.clear();
}
public void addItems(List<Music> music) {
// Clear the old items. I only do this so that I don't have to do duplicating checks on the music items.
mMusic.clear();
// Add the new music list.
mMusic.addAll(music);
notifyItemRangeInserted(0, music.size());
}
/**
* Clears the {@link Music} items inside of this adapter.
*/
@Override
public MusicViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View v = inflater.inflate(R.layout.list_item, parent, false);
MusicViewHolder musicViewHolder = new MusicViewHolder(v);
return musicViewHolder;
}
@Override
public void onBindViewHolder(MusicViewHolder holder, final int position) {
final Music music = mMusic.get(position);
holder.itemView.setLongClickable(true);
// Check the Bitmap cache for the album art first..
final Bitmap bitmap = mBitmapCache.get(music.getAlbumId());
// If the bitmap is not null, then use the cached images.
if(bitmap != null){
holder.icon.setImageBitmap(bitmap);
}
else {
// No album art could be found in the cache try reloading it.
// In a real work example you should check that this value is not some junk value indicating that their is no album artwork.
loadAlbumArt(holder.icon, music.getAlbumId());
}
holder.artist.setText(music.getArtist());
holder.title.setText(music.getTitle());
final Uri trackuri= ContentUris.withAppendedId(
android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, music.getId());
final Uri turi= ContentUris.withAppendedId(
android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, music.getId());
holder.button8.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, Playrecord.class);
intent.setData(trackuri);
mContext.startActivity(intent);
}
});
holder.button9.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File file = new File(String.valueOf(trackuri));
file.delete();
mMusic.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position,mMusic.size());
Toast.makeText(mContext,"Removed : " , Toast.LENGTH_SHORT).show();
}
});
}
/**
* Helper method for asynchronously loading album art.
* @param icon
* @param albumId
*/
public void loadAlbumArt(ImageView icon, long albumId) {
// Check the current album art task if any and cancel it, if it is loading album art that doesn't match the specified album id.
if(cancelLoadTask(icon, albumId)) {
// There was either no task running or it was loading a different image so create a new one to load the proper image.
LoadAlbumArt loadAlbumArt = new LoadAlbumArt(icon, mContext);
// Store the task inside of the async drawable.
AsyncDrawable drawable = new AsyncDrawable(mContext.getResources(), mPlaceholder.getBitmap(),loadAlbumArt);
icon.setImageDrawable(drawable);
loadAlbumArt.execute(albumId);
}
}
/**
* Helper method cancelling {@link LoadAlbumArt}.
*
* @param icon
* @param albumId
* @return
*/
public boolean cancelLoadTask(ImageView icon, long albumId) {
LoadAlbumArt loadAlbumArt = (LoadAlbumArt) getLoadTask(icon);
// If the task is null return true because we want to try and load the album art.
if(loadAlbumArt == null) {
return true;
}
if(loadAlbumArt != null) {
// If the album id differs cancel this task because it cannot be recycled for this imageview.
if(loadAlbumArt.albumId != albumId) {
loadAlbumArt.cancel(true);
return true;
}
}
return false;
}
/**
* Helper method for extracting an {@link LoadAlbumArt}.
* @param icon
* @return
*/
public AsyncTask getLoadTask(ImageView icon) {
LoadAlbumArt task = null;
Drawable drawable = icon.getDrawable();
if(drawable instanceof AsyncDrawable) {
task = ((AsyncDrawable) drawable).getLoadArtworkTask();
}
return task;
}
public void remove(long itemId) {
}
private class LoadAlbumArt extends AsyncTask<Long, Void, Bitmap> {
// URI that points to the AlbumArt database.
private final Uri albumArtURI = Uri.parse("content://media/external/audio/albumart");
public WeakReference<ImageView> mIcon;
// Holds a publicly accessible albumId to be checked against.
public long albumId;
public Context mContext;
int width, height;
public LoadAlbumArt(ImageView icon, Context context) {
// Store a weak reference to the imageView.
mIcon = new WeakReference<ImageView>(icon);
// Store the width and height of the imageview.
// This is necessary for properly scalling the bitmap.
width = icon.getWidth();
height = icon.getHeight();
mContext = context;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
if(isCancelled() || bitmap == null){
return;
}
// Check to make sure that the imageview has not been garbage collected as well as the
// LoadArtworkTask is the same as this one.
if(mIcon != null && mIcon.get() != null) {
ImageView icon = mIcon.get();
Drawable drawable = icon.getDrawable();
if(drawable instanceof AsyncDrawable) {
LoadAlbumArt task = ((AsyncDrawable) drawable).getLoadArtworkTask();
// Make sure that this is the same task as the one current stored inside of the ImageView's drawable.
if(task != null && task == this) {
icon.setImageBitmap(bitmap);
}
}
}
mBitmapCache.put(albumId, bitmap);
super.onPostExecute(bitmap);
}
@Override
protected Bitmap doInBackground(Long... params) {
// AsyncTask are not guaranteed to start immediately and could be cancelled somewhere in between calling doInBackground.
if(isCancelled()){
return null;
}
albumId = params[0];
// Append the albumId to the end of the albumArtURI to create a new Uri that should point directly to the album art if it exist.
Uri albumArt = ContentUris.withAppendedId(albumArtURI, albumId);
Bitmap bmp = null;
return bmp;
}
}
/**
* Custom drawable that holds a LoadArtworkTask
*/
private static class AsyncDrawable extends BitmapDrawable {
WeakReference<LoadAlbumArt> loadArtworkTaskWeakReference;
public AsyncDrawable(Resources resources, Bitmap bitmap, LoadAlbumArt task) {
super(resources, bitmap);
// Store the LoadArtwork task inside of a weak reference so it can still be garbage collected.
loadArtworkTaskWeakReference = new WeakReference<LoadAlbumArt>(task);
}
public LoadAlbumArt getLoadArtworkTask() {
return loadArtworkTaskWeakReference.get();
}
}
@Override
public int getItemCount() {
return mMusic.size();
}
/**
* Custom ViewHolder that represents the List Item.
*/
public static class MusicViewHolder extends RecyclerView.ViewHolder {
ImageView icon;
TextView title;
TextView artist;
Button button8;
Button deleteButton;
public MusicViewHolder(View itemView) {
super(itemView);
icon = (ImageView) itemView.findViewById(R.id.icon);
title = (TextView) itemView.findViewById(R.id.title);
artist = (TextView)itemView.findViewById(R.id.subtitle);
button8 = (Button) itemView.findViewById(R.id.button8);
deleteButton = (Button) itemView.findViewById(R.id.deleteButton);
}
}
}
答案 0 :(得分：1)
像这样删除
mContext.getContentResolver().delete(trackuri,null, null);
更新：与file.delete();并非单独使用
mContext.getContentResolver().delete(trackuri,null, null);
if (file.exists()) {
file.delete();
}