【发布时间】：2018-01-11 16:24:34
【问题描述】：
在我的音乐应用程序中，我试图获取专辑封面，但无法获取。我不知道这有什么问题。我尝试了一些代码，告诉我出了什么问题。
这是日志。 java.lang.IllegalStateException：无法读取第 0 行， 来自 CursorWindow 的 col -1。确保光标已初始化 在从中访问数据之前正确。 在 android.database.CursorWindow.nativeGetString(Native Method) 在 android.database.CursorWindow.getString(CursorWindow.java:438) 在 android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:51) 在 android.database.CursorWrapper.getString(CursorWrapper.java:137) 在 layout.BlankFragment2.loadSongs(BlankFragment2.java:228) 在 layout.BlankFragment2.checkUserPermission(BlankFragment2.java:186) 在 layout.BlankFragment2.onCreateView(BlankFragment2.java:143)
public class BlankFragment2 extends Fragment {
private ArrayList<songInfo> _songs = new ArrayList<songInfo>();
RecyclerView recyclerView;
SeekBar seekBar;
public songAdapter songAdapter1;
ImageView album_art;
MediaPlayer mediaPlayer;
private Handler myHandler = new Handler();
//byte[] art;
String id;
View rootView;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private BlankFragment.OnFragmentInteractionListener mListener;
public BlankFragment2() {
// Required empty public constructor
}
// TODO: Rename and change types and number of parameters
public static BlankFragment newInstance(String param1, String param2) {
BlankFragment fragment = new BlankFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView= inflater.inflate(R.layout.fragment_blank_fragment2, container, false);
recyclerView = (RecyclerView)rootView. findViewById(R.id.recyclerView);
seekBar = (SeekBar) rootView.findViewById(R.id.seekBar);
album_art=(ImageView)rootView.findViewById(R.id.albumArt);
songAdapter1 = new songAdapter(getActivity(),_songs);
recyclerView.setAdapter(songAdapter1);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
linearLayoutManager.getOrientation());
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.addItemDecoration(dividerItemDecoration);
songAdapter1.setOnItemClickListener(new songAdapter.OnItemClickListener() {
public void onItemClick(RecyclerView.ViewHolder holder, View view, final songInfo obj, int position) {
if(mediaPlayer.isPlaying()){
mediaPlayer.stop();
mediaPlayer.reset();
mediaPlayer.release();
mediaPlayer = null;
}else {
Runnable runnable = new Runnable() {
@Override
public void run() {
try {
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(obj.getSongUrl());
mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
seekBar.setProgress(0);
seekBar.setMax(mediaPlayer.getDuration());
Log.d("Prog", "run: " + mediaPlayer.getDuration());
}
});
}catch (Exception e){}
}
};
myHandler.postDelayed(runnable,100);
}
}
});
checkUserPermission();
Thread t = new runThread();
t.start();
return rootView;
}
public class runThread extends Thread {
@Override
public void run() {
while (true) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.d("Runwa", "run: " + 1);
if (mediaPlayer != null) {
seekBar.post(new Runnable() {
@Override
public void run() {
seekBar.setProgress(mediaPlayer.getCurrentPosition());
}
});
Log.d("Runwa", "run: " + mediaPlayer.getCurrentPosition());
}
}
}
}
private void checkUserPermission(){
if(Build.VERSION.SDK_INT>=23){
if(ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED){
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},123);
return;
}
}
loadSongs();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode){
case 123:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED){
loadSongs();
}else{
Toast.makeText(getContext(), "Permission Denied", Toast.LENGTH_SHORT).show();
checkUserPermission();
}
break;
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
private void loadSongs() {
MediaMetadataRetriever metaRetriver = new MediaMetadataRetriever();
Cursor mcursor = getContext().getContentResolver().query(MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI,
new String[]{MediaStore.Audio.Albums._ID, MediaStore.Audio.Albums.ALBUM_ART},
MediaStore.Audio.Albums._ID + "=?",
new String[]{String.valueOf(id)},
null);
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String selection = MediaStore.Audio.Media.IS_MUSIC + "!=0";
Cursor cursor = getContext().getContentResolver().query(uri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
String url = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
String coverPath = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART));
Drawable img = Drawable.createFromPath(coverPath);
ImageView coverAlbum=(ImageView)rootView.findViewById(R.id.albumArt);
coverAlbum.setImageDrawable(img);
songInfo s = new songInfo(name, artist, url);
_songs.add(s);
}
while (cursor.moveToNext());
cursor.close();
recyclerView.getAdapter().notifyDataSetChanged();
}
}
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (BlankFragment.OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
void onFragmentInteraction(Uri uri);
}
}
【问题讨论】：
标签： android android-mediaplayer