当我重新打开我的app文件时，其长度为零 如何永久删除它？
我正在使用列表视图使用Media Store显示外部存储中的所有歌曲，并添加了删除选项。
当我重新打开我的应用程序歌曲文件时删除文件后再次出现在列表视图中但文件长度为零。
请参阅f1 = open(argv[1], "r")
f2 = str(f1.read())
farr = list(f2)
size1 = len(farr)
size2 = input("Size:")
size = width, height = int(size2), int(size2);
size1 + 1
#MAKING THE IMAGE
img = Image.new('RGB', size, "white" )
map = img.load()
print(map[0,0])
Rw,Gw,Bw = [255,255,255]
Rb,Gb,Bb = [0,0,0]
def Converter(num,x,y):
while int(size1) != int(num):
if farr[num - 1: + int(num)] == ["0"]:
img.putpixel((x,y), (Rw,Gw,Bw))
x = x + 1
elif farr[num -1: + int(num)] == ["1"]:
img.putpixel((x,y), (Rb,Gb,Bb))
x = x + 1
elif farr[num -1: + int(num)] == [" "]:
y = y + 1
else:
print("nothing")
num = num + 1
Converter(1,1,1)
img.show()
了解删除：
onClickListenerlogcat的：
public class TracksFragment extends Fragment {
songDetailloader loader = new songDetailloader();
ArrayList<Songs> give = new ArrayList<>();
public int pos = -1;
MediaPlayer mp ;
MusicService musicService;
boolean mBound;
Context context;
public TracksFragment() {
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable final ViewGroup container, @Nullable Bundle savedInstanceState)
{
View v =inflater.inflate(R.layout.listviewofsongs,container,false);
final ListView listView = (ListView) v.findViewById(R.id.listView);
loader.set(getContext());
give = loader.allsongs();
final ListViewAdapter listViewAdapter = new ListViewAdapter(getContext(),give);
listView.setAdapter(listViewAdapter);
listView.setSelector(R.drawable.selector);
new Thread(new Runnable() {
@Override
public void run() {
Intent i = new Intent(getActivity(),MusicService.class);
getActivity().bindService(i, serviceConnection, Context.BIND_AUTO_CREATE);
}
}).start();
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Log.d("Uri of ",""+give.get(position).getSonguri());
musicService.setplaylist(give,position);
musicService.setMediaPlayer();
view.setSelected(true);
}
});
listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
View v =LayoutInflater.from(getContext()).inflate(R.layout.select_dialog_layout,null);
builder.setView(v);
builder.setTitle(give.get(position).gettitle()+"\n "+give.get(position).getalbum());
builder.create();
final AlertDialog d=builder.show();
//seting click listner.....
TextView play = (TextView) v.findViewById(R.id.dialogplay);
TextView playnext = (TextView) v.findViewById(R.id.dialogplaynext);
TextView queue = (TextView) v.findViewById(R.id.dialogqueue);
TextView fav = (TextView) v.findViewById(R.id.dialogaddtofav);
TextView album = (TextView) v.findViewById(R.id.dialogalbum);
TextView artist = (TextView) v.findViewById(R.id.dialogartist);
TextView playlist = (TextView) v.findViewById(R.id.dialogaddtoplaylsit);
TextView share = (TextView) v.findViewById(R.id.dialogshare);
TextView delete = (TextView) v.findViewById(R.id.dialogdelete);
play.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
File f= new File(give.get(position).getSonguri().getLastPathSegment());
Log.d("LENGTH IS",""+f.length());
musicService.setplaylist(give,position);
musicService.setMediaPlayer();
d.dismiss();
}
});
playnext.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
queue.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
fav.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
DataBaseClass db = new DataBaseClass(getContext());
int i=db.insetintoliked(give.get(position));
if(i==1)
{
Toast.makeText(getContext(),"Added to Favorites",Toast.LENGTH_SHORT).show();
}
else
Toast.makeText(getContext(),"Already in Favorites",Toast.LENGTH_SHORT).show();
}
});
album.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
Intent i = new Intent( getActivity() , AlbumDetail.class);
Bundle b= new Bundle();
b.putCharSequence("album",give.get(position).getalbum());
i.putExtras(b);
startActivity(i);
}
});
artist.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
playlist.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
}
});
delete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder b = new AlertDialog.Builder(getContext());
b.setMessage("Audio '"+give.get(position).gettitle()+"' will be deleted permanently !");
b.setTitle("Delete ?");
b.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
d.dismiss();
}
});
b.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
loader.deleteSong(getContext(),give.get(position).getPosition());
File f= new File(give.get(position).getSonguri().getPath());
boolean b = f.delete();
Log.d("Is file exist",f.exists()+"");
Log.d("File Length",""+f.length());
Log.d("Return value",""+b);
give.remove(position); // give is Arraylist of Songs(datatype);
listViewAdapter.notifyDataSetChanged();
if(b)
{
Toast.makeText(getContext(),"Deleted",Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getContext(),"Fail to Delete",Toast.LENGTH_SHORT).show();
}
}
});
b.create().show();
d.dismiss();
}
});
share.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
d.dismiss();
Intent share = new Intent(Intent.ACTION_SEND);
share.setType("audio/*");`enter code here`
share.putExtra(Intent.EXTRA_STREAM, give.get(position).getSonguri());
startActivity(Intent.createChooser(share, "Share Sound File"));
}
});
return true;
}
});
container.addView(v);
return v;
}
}