我将在我的音乐播放器上制作一个安卓应用程序,在其中使用ListView填充了设备中所有的歌曲,但在安卓6.0上打开它时,我的应用程序会崩溃。当我在应用信息中手动授予存储权限后,它就不再崩溃了,并且我的歌曲也会显示出来。
我已经使用了安卓6.0的请求权限功能,它会询问用户是否允许访问存储空间,但是它不再显示列表了。我被卡住了...!
MainActivity.java
我已经使用了安卓6.0的请求权限功能,它会询问用户是否允许访问存储空间,但是它不再显示列表了。我被卡住了...!
MainActivity.java
public class MainActivity extends AppCompatActivity implements MediaPlayerControl {
private ArrayList<Song> songList;
private ListView songView;
private MusicController controller;
private MusicService musicSrv;
private Intent playIntent;
private boolean musicBound=false;
private boolean paused=false, playbackPaused=false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
songView = (ListView) findViewById(R.id.song_list);
songList = new ArrayList<Song>();
//Android 6.0
if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
} else {
}
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},1002);
}
}
//Android 6.0
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode){
case 1002:
if(grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED){
getSongList();
// List songs in Alphabetical Order
Collections.sort(songList, new Comparator<Song>() {
public int compare(Song a, Song b) {
return a.getTitle().compareTo(b.getTitle());
}
});
SongAdapter songAdt = new SongAdapter(this, songList);
songView.setAdapter(songAdt);
setController();
}else{
}
return;
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_shuffle:
musicSrv.setShuffle();
break;
case R.id.action_end:
stopService(playIntent);
musicSrv = null;
System.exit(0);
break;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onStart() {
super.onStart();
if(playIntent==null) {
playIntent = new Intent(this, MusicService.class);
bindService(playIntent, musicConnection, Context.BIND_AUTO_CREATE);
startService(playIntent);
}
}
@Override
protected void onPause() {
super.onPause();
paused=true;
}
@Override
protected void onResume() {
super.onResume();
if(paused){
setController();
paused=false;
}
}
@Override
protected void onStop() {
controller.hide();
super.onStop();
}
@Override
protected void onDestroy() {
stopService(playIntent);
musicSrv=null;
super.onDestroy();
}
public void songPicked(View view){
musicSrv.setSong(Integer.parseInt(view.getTag().toString()));
musicSrv.playSong();
if(playbackPaused){
setController();
playbackPaused=false;
}controller.show(0);
}
//connect to the service
private ServiceConnection musicConnection = new ServiceConnection(){
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
MusicService.MusicBinder binder = (MusicService.MusicBinder)service;
//get service
musicSrv = binder.getService();
//pass list
musicSrv.setList(songList);
musicBound = true;
}
@Override
public void onServiceDisconnected(ComponentName name) {
musicBound = false;
}
};
public void getSongList() {
//retrieve song info
ContentResolver musicResolver = getContentResolver();
Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);
if(musicCursor!=null && musicCursor.moveToFirst()){
//get columns
int titleColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media.TITLE);
int idColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media._ID);
int artistColumn = musicCursor.getColumnIndex
(android.provider.MediaStore.Audio.Media.ARTIST);
//add songs to list
do {
long thisId = musicCursor.getLong(idColumn);
String thisTitle = musicCursor.getString(titleColumn);
String thisArtist = musicCursor.getString(artistColumn);
songList.add(new Song(thisId, thisTitle, thisArtist));
}
while (musicCursor.moveToNext());
}
}