您好我正在创建音乐播放器应用。
我遇到一个问题，当我点击listview时它会播放歌曲。
当我再一次点击列表视图时，歌曲就会一起播放。
上一首歌并没有停止。
我遵循了许多tuts和博客以及stackoverflow的答案，但没有任何工作。
这是我的活动，其中包含歌曲列表视图： -
public class songlist extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private ListView lv_songlist;
public Cursor cursor;
private MediaCursorAdapter mediaAdapter = null;
private String currentFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.songlist);
lv_songlist = (ListView) findViewById(R.id.songlist);
cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null, null);
if (null != cursor)
{
cursor.moveToFirst();
mediaAdapter = new MediaCursorAdapter(this, R.layout.listitem, cursor);
lv_songlist.setAdapter(mediaAdapter);
lv_songlist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
currentFile = (String) view.getTag();
Intent myIntent = new Intent(songlist.this,
now_playing.class);
myIntent.putExtra("song",""+currentFile);
myIntent.putExtra("cursor-position",cursor.getPosition());
startActivity(myIntent);
}
});
}
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent myIntent = new Intent(songlist.this,
now_playing.class);
myIntent.putExtra("song","");
startActivity(myIntent);
}
});
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START))
{
drawer.closeDrawer(GravityCompat.START);
}
else
{
super.onBackPressed();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.songlist, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.nav_camera)
{
}
else if (id == R.id.nav_gallery) {
} else if (id == R.id.nav_slideshow) {
} else if (id == R.id.nav_manage) {
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
private class MediaCursorAdapter extends SimpleCursorAdapter {
public MediaCursorAdapter(Context context, int layout, Cursor c) {
super(context, layout, c,
new String[]{MediaStore.MediaColumns.DISPLAY_NAME, MediaStore.MediaColumns.TITLE, MediaStore.Audio.AudioColumns.DURATION},
new int[]{R.id.displayname, R.id.title, R.id.duration});
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView title = (TextView) view.findViewById(R.id.title);
TextView name = (TextView) view.findViewById(R.id.displayname);
TextView duration = (TextView) view.findViewById(R.id.duration);
name.setText(cursor.getString(
cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME)));
title.setText(cursor.getString(
cursor.getColumnIndex(MediaStore.MediaColumns.TITLE)));
long durationInMs = Long.parseLong(cursor.getString(
cursor.getColumnIndex(MediaStore.Audio.AudioColumns.DURATION)));
Duration d = new Duration();
String durationInMin = d.convertDuration(durationInMs);
duration.setText("" + durationInMin);
view.setTag(cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DATA)));
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(context);
View v = inflater.inflate(R.layout.listitem, parent, false);
bindView(v, context, cursor);
return v;
}
}
}
这是我一起播放歌曲的音乐播放活动： -
public class now_playing extends AppCompatActivity implements View.OnClickListener{
private MediaPlayer mp = new MediaPlayer();
private Cursor cursor;
private RelativeLayout rl_album;
private TextView Title_now_playing,duration_now_playing;
private String Title,Duration,currentSong;
private int cursorPosition;
private ImageButton playPrev,playNext,seekFwd,seekBwd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.now_playing);
setTitle("");
cursor = getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null, null);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
android.support.v7.app.ActionBar mActionBar = getSupportActionBar();
LayoutInflater mInflater = LayoutInflater.from(this);
View mCustomView = mInflater.inflate(R.layout.custom_layout_now_playing_for_action_bar, null);
Title_now_playing = (TextView) mCustomView.findViewById(R.id.title_text);
duration_now_playing = (TextView) findViewById(R.id.duration);
playNext = (ImageButton) findViewById(R.id.playNext);
rl_album = (RelativeLayout) findViewById(R.id.rl_album);
Title_now_playing.setText(Title);
mActionBar.setCustomView(mCustomView);
mActionBar.setDisplayShowCustomEnabled(true);
Intent in = getIntent();
currentSong = in.getStringExtra("song");
cursorPosition = in.getIntExtra("cursor-position",1);
displayDetails();
playNext.setOnClickListener(this);
}
void displayDetails(){
mp.stop();
mp.reset();
if(!currentSong.equals(""))
{
cursor.move(cursorPosition+1);
try {
mp.setDataSource(currentSong);
mp.prepare();
mp.start();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Title = cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME));
int duration = cursor.getColumnIndex
(MediaStore.Audio.Media.DURATION);
long SongDuration = cursor.getLong(duration);
com.example.davda.musicmain.Duration d = new Duration();
Duration = d.convertDuration(SongDuration);
duration_now_playing.setText(Duration);
Title_now_playing.setText(Title);
ContentResolver musicResolve = getContentResolver();
Uri smusicUri = MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI;
Cursor musicCursorTogetAlbum =musicResolve.query(smusicUri,null //should use where clause(_ID==albumid)
,null, null, null);
musicCursorTogetAlbum.move(cursorPosition+1); //i put only one song in my external storage to keep things simple;
try{
int x = musicCursorTogetAlbum.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART);
String thisArt = musicCursorTogetAlbum.getString(x);
Bitmap bm = BitmapFactory.decodeFile(thisArt);
Drawable dr = new BitmapDrawable(getResources(), bm);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
rl_album.setBackground(dr);
}
}catch (RuntimeException re)
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
rl_album.setBackgroundColor(Color.BLACK);
}
}
}
}
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.now_playing_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Intent myIntent = new Intent(now_playing.this,
songlist.class);
startActivity(myIntent);
return true;
case R.id.custom_equalizer:
Toast.makeText(now_playing.this,"Custom Equalizer button pressed. Good broooooooooooooooooooooo...",Toast.LENGTH_LONG).show();
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.playNext: {
cursor.moveToNext();
currentSong = cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DATA));
displayDetails();
}
}
}
}
答案 0 :(得分：2)
因为您每次都在活动中创建新的MediaPlayer实例。
使用单个MediaPlayer实例。
创建一个单例类，并从那里使用MediaPlayer。
或者您可以在ListView活动中将MediaPlayer设为公共静态。
public static MediaPlayer mp = new MediaPlayer();
在 now_playing活动
中使用此MediaPlayer答案 1 :(得分：1)
我遇到了同样的问题并且修复了这样的问题。更改您的项目要求。
全局声明您的mediaPlayer实例
static MediaPlayer mediaPlayer = new MediaPlayer();
创建AudioManager和音量设置（注意：我使用Max Volume播放声音）：
AudioManager mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
int maxVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, maxVolume, AudioManager.FLAG_PLAY_SOUND);
然后将此代码放在点击
上的播放按钮上 try {
if (mediaPlayer != null) {
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
}
mediaPlayer.release();
mediaPlayer = null;
}
mediaPlayer.setDataSource(filePath);
mediaPlayer.prepare();
mediaPlayer.start();
} catch (IOException e) {
e.printStackTrace();
}