我是Android开发的新手，目前我正在开发一个简单的媒体播放器应用程序。
根据我的项目，我定义了三个片段。第一个片段是播放器片段，它显示媒体播放器控件并播放歌曲。第二个片段是包含歌曲列表的播放列表。第三个片段是最近的播放列表，其中包含最近播放的歌曲。
我的问题是如何从播放列表片段中选择新歌时停止播放旧歌？
PLAYER FRAGMENT。
public class Player extends Fragment implements SeekBar.OnSeekBarChangeListener{
private ImageButton btnPlay;
private ImageButton btnForward;
private ImageButton btnBackward;
private ImageButton btnNext;
private ImageButton btnPrevious;
private ImageButton btnRepeat;
private ImageButton btnShuffle;
private SeekBar songProgressBar;
private TextView songTitleLabel;
private TextView songCurrentDurationLabel;
private TextView songTotalDurationLabel;
// Media Player
public static MediaPlayer mp,mp2;
VisualizerView mVisualizerView;
SliderView sl;
private Visualizer mVisualizer;
// Handler to update UI timer, progress bar etc,.
private Handler mHandler = new Handler();;
private SongsManager songManager;
private Utilities utils;
private int seekForwardTime = 5000; // 5000 milliseconds
private int seekBackwardTime = 5000; // 5000 milliseconds
private int currentSongIndex = 0;
private boolean isShuffle = false;
private boolean isRepeat = false;
private ArrayList<SongModel> songsList = new ArrayList<SongModel>();
int songIndex;
SongAdapter songAdapter;
public Player(int position) {
songIndex = position;
}
public Player() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View android = inflater.inflate(R.layout.player, container, false);
/*ClickWheel wheel = (ClickWheel) android.findViewById(R.id.wheel);
wheel.getModel().addListener(this);*/
// variable initialization for button
return android;
}
@Override
public void onViewCreated(View v, Bundle savedInstanceState) {
super.onViewCreated(v, savedInstanceState);
btnPlay = (ImageButton)getView().findViewById(R.id.btnPlay);
btnForward = (ImageButton) getView().findViewById(R.id.btnForward);
btnBackward = (ImageButton) getView().findViewById(R.id.btnBackward);
btnNext = (ImageButton) getView().findViewById(R.id.btnNext);
btnPrevious = (ImageButton) getView().findViewById(R.id.btnPrevious);
btnRepeat = (ImageButton) getView().findViewById(R.id.btnRepeat);
btnShuffle = (ImageButton) getView().findViewById(R.id.btnShuffle);
songProgressBar = (SeekBar) getView().findViewById(R.id.songProgressBar);
songTitleLabel = (TextView) getView().findViewById(R.id.songTitle);
songTitleLabel.setSelected(true);
songTitleLabel.setEllipsize(TextUtils.TruncateAt.MARQUEE);
songTitleLabel.setSingleLine(true);
songCurrentDurationLabel = (TextView) getView().findViewById(R.id.songCurrentDurationLabel);
songTotalDurationLabel = (TextView) getView().findViewById(R.id.songTotalDurationLabel);
mp = new MediaPlayer();
songManager = new SongsManager();
utils = new Utilities();
songProgressBar.setOnSeekBarChangeListener(this);
songsList = songManager.getPlayList();
if (songIndex == 0) {
playSong(0);
} else {
playSong(songIndex);
}
btnPlay.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// check for already playing
if (mp.isPlaying()) {
if (mp != null) {
mp.pause();
btnPlay.setImageResource(R.drawable.btn_play);
}
} else {
// Resume song
if (mp != null) {
mp.start();
btnPlay.setImageResource(R.drawable.btn_pause);
}
}
}
});
btnForward.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
int currentPosition = mp.getCurrentPosition();
if(currentPosition + seekForwardTime <= mp.getDuration()){
mp.seekTo(currentPosition + seekForwardTime);
}else{
mp.seekTo(mp.getDuration());
}
}
});
btnBackward.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
int currentPosition = mp.getCurrentPosition();
if(currentPosition - seekBackwardTime >= 0){
mp.seekTo(currentPosition - seekBackwardTime);
}else{
mp.seekTo(0);
}
}
});
btnNext.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if(currentSongIndex < (songsList.size() - 1)){
playSong(currentSongIndex + 1);
currentSongIndex = currentSongIndex + 1;
}else{
playSong(0);
currentSongIndex = 0;
}
}
});
btnPrevious.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if(currentSongIndex > 0){
playSong(currentSongIndex - 1);
currentSongIndex = currentSongIndex - 1;
}else{
playSong(songsList.size() - 1);
currentSongIndex = songsList.size() - 1;
}
}
});
btnRepeat.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if(isRepeat){
isRepeat = false;
Toast.makeText(getActivity().getApplicationContext(), "Repeat is OFF", Toast.LENGTH_SHORT).show();
btnRepeat.setImageResource(R.drawable.btn_repeat);
}else{
isRepeat = true;
Toast.makeText(getActivity().getApplicationContext(), "Repeat is ON", Toast.LENGTH_SHORT).show();
isShuffle = false;
btnRepeat.setImageResource(R.drawable.btn_repeat_focused);
btnShuffle.setImageResource(R.drawable.btn_shuffle);
}
}
});
btnShuffle.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
if(isShuffle){
isShuffle = false;
Toast.makeText(getActivity().getApplicationContext(), "Shuffle is OFF", Toast.LENGTH_SHORT).show();
btnShuffle.setImageResource(R.drawable.btn_shuffle);
}else{
isShuffle= true;
Toast.makeText(getActivity().getApplicationContext(), "Shuffle is ON", Toast.LENGTH_SHORT).show();
isRepeat = false;
btnShuffle.setImageResource(R.drawable.btn_shuffle_focused);
btnRepeat.setImageResource(R.drawable.btn_repeat);
}
}
});
}
public void playSong(int songIndex) {
try {
Log.e("playSong()...", "....is called");
mp.reset();
mp.setDataSource(songsList.get(songIndex).getSongPath());
mp.prepare();
songProgressBar.setProgress(0);
songProgressBar.setMax(100);
String songTitle = songsList.get(songIndex).getSongTitle();
songTitleLabel.setText(songTitle);
btnPlay.setImageResource(R.drawable.btn_pause);
mp.start();
updateProgressBar();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private Runnable mUpdateTimeTask = new Runnable() {
public void run() {
long totalDuration = mp.getDuration();
long currentDuration = mp.getCurrentPosition();
songTotalDurationLabel.setText(""+utils.milliSecondsToTimer(totalDuration));
songCurrentDurationLabel.setText("" + utils.milliSecondsToTimer(currentDuration));
int progress =(int)(utils.getProgressPercentage(currentDuration, totalDuration));
songProgressBar.setProgress(progress);
mHandler.postDelayed(this, 100);
}
};
private void updateProgressBar() {
mHandler.postDelayed(mUpdateTimeTask, 100);
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
}
public void onStartTrackingTouch(SeekBar seekBar) {
mHandler.removeCallbacks(mUpdateTimeTask);
}
public void onStopTrackingTouch(SeekBar seekBar) {
mHandler.removeCallbacks(mUpdateTimeTask);
int totalDuration = mp.getDuration();
int currentPosition = utils.progressToTimer(seekBar.getProgress(), totalDuration);
mp.seekTo(currentPosition);
updateProgressBar();
}}
PLAYLIST FRAGMENT
public class Playlists extends ListFragment {
EditText edtSearch;
SongAdapter songAdapter;
ArrayList<SongModel> songList = new ArrayList<SongModel>();
SongsManager songsManager = new SongsManager();
// Songs list
public ArrayList<SongModel> songsList = new ArrayList<>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View windows = inflater.inflate(R.layout.playlist, container, false);
return windows;
}
@Override
public void onViewCreated(View v, Bundle savedInstanceState) {
super.onViewCreated(v, savedInstanceState);
getListView().setFastScrollEnabled(true);
//ListView animation
LayoutAnimationController controller
= AnimationUtils.loadLayoutAnimation(
getActivity(), R.anim.list_layout_controller);
getListView().setLayoutAnimation(controller);
edtSearch = (EditText)getView().findViewById(R.id.search);
final ArrayList<SongModel> songsListData = songsManager.songList;
Log.i("songsListData...",""+songsListData.size());
SongsManager plm = new SongsManager();
// get all songs from sdcard
this.songsList = plm.getPlayList();
// looping through playlist
for (int i = 0; i < songsListData.size(); i++) {
// creating new HashMap
SongModel song = songsListData.get(i);
// adding HashList to ArrayList
songsListData.add(song);
}
songAdapter = new SongAdapter(getActivity(),songsList);
setListAdapter(songAdapter);
// selecting single ListView item
ListView lv = getListView();
// listening to single listitem click
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View arg0,
int position, long id) {
Log.i("Index", "..." + position);
songAdapter.setSelectedIndex(position);
Intent i = new Intent(getActivity().getApplicationContext(),Main.class);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK);
SongModel songModel = (SongModel) songAdapter.getItem(position);
int indexOfSong = songAdapter.songsList.indexOf(songModel);
// Sending songIndex to PlayerActivity
i.putExtra("songIndex", indexOfSong);
getActivity().setResult(100, i);
startActivityForResult(i, 100);
/*Player.mp.stop();
Player.mp.release();*/
//putting song in recentSongList arraylist
SongModel model = (SongModel) songAdapter.getItem(position);
model.setSongTitle(songModel.getSongTitle());
model.setSongPath(songModel.getSongPath());
Constant.recentSongList.add(model);
Log.i("recentSongList...","..."+Constant.recentSongList.size());
getActivity().finish();
}
});
lv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
removeItemFromList(position);
return true;
}
private void removeItemFromList(int position) {
final int deletePosition = position;
AlertDialog.Builder alert = new AlertDialog.Builder(
getActivity());
alert.setTitle("Delete");
alert.setMessage("Do you want delete this song?");
alert.setPositiveButton("YES", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TOD O Auto-generated method stub
// main code on after clicking yes
songsList.remove(deletePosition);
songAdapter.notifyDataSetChanged();
songAdapter.notifyDataSetInvalidated();
}
});
alert.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.dismiss();
}
});
alert.show();
}
});
edtSearch.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence cs, int start, int before, int count) {
}
@Override
public void afterTextChanged(Editable s) {
String text = edtSearch.getText().toString().toLowerCase(Locale.getDefault());
songAdapter.filter(text);
}
});
}
@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (this.isVisible()) {
// If we are becoming invisible, then...
Log.d("setUserVisibleHint()...", "PlayList...Visible");
if (!isVisibleToUser) {
Log.d("setUserVisibleHint()...", "PlayList...notVisible");
// TODO stop audio playback
}
}
}
如果有人知道该怎么做，请帮助我。
答案 0 :(得分：1)
在播放列表片段中删除此Player.mp.release();
像这样编辑你的Listview onItemCLickListner
@Override
public void onItemClick(AdapterView<?> parent, View arg0,
int position, long id) {
Log.i("Index", "..." + position);
songAdapter.setSelectedIndex(position);
Intent i = new Intent(getActivity().getApplicationContext(),Main.class);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK);
SongModel songModel = (SongModel) songAdapter.getItem(position);
int indexOfSong = songAdapter.songsList.indexOf(songModel);
// Sending songIndex to PlayerActivity
i.putExtra("songIndex", indexOfSong);
getActivity().setResult(100, i);
startActivityForResult(i, 100);
Player.mp.stop();
//putting song in recentSongList arraylist
SongModel model = (SongModel) songAdapter.getItem(position);
model.setSongTitle(songModel.getSongTitle());
model.setSongPath(songModel.getSongPath());
Constant.recentSongList.add(model);
Log.i("recentSongList...","..."+Constant.recentSongList.size());
getActivity().finish();
}
});
我希望这项工作......