我制作了 Android 应用程序，在其中我从移动存储读取所有音频歌曲并将所有歌曲添加到自定义 ListView 。在我的 ListView 中，有一个简单的 TextView ，其中放置了歌曲，现在我想将点击监听器添加到列表中，并从 ListView 中获取这些歌曲并传递到另一个 Activity 来播放歌曲。我有两个类 MainActivity.java
public class MainActivity extends AppCompatActivity {
ListView lv;
String[] items;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView) findViewById(R.id.lvPlaylist);
final ArrayList<File> mySongs = findSongs(Environment.getExternalStorageDirectory());
items = new String[mySongs.size()];
for (int i = 0; i < mySongs.size(); i++) {
//toast(mySongs.get(i).getName().toString());
items[i] = mySongs.get(i).getName().toString().replace(".mp3", "").replace(".wav", "");
}
ArrayAdapter<String> adp = new ArrayAdapter<String>(getApplicationContext(), R.layout.song_layout, R.id.textView, items);
lv.setAdapter(adp);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long l) {
Intent intent = new Intent(MainActivity.this,Player.class);
intent.putExtra("pos",position);
intent.putExtra("songList",mySongs);
startActivity(intent);
// startActivity(new Intent(getApplicationContext(),Player.class).putExtra("pos",position).putExtra("songlist",mySongs));
}
});
}
public ArrayList<File> findSongs(File root) {
ArrayList<File> al = new ArrayList<File>();
File[] files = root.listFiles();
for (File singleFile : files) {
if (singleFile.isDirectory() && !singleFile.isHidden()) {
al.addAll(findSongs(singleFile));
} else {
if (singleFile.getName().endsWith(".mp3") || singleFile.getName().endsWith(".wav")) {
al.add(singleFile);
}
}
}
return al;
}
public void toast(String text) {
Toast.makeText(getApplicationContext(), text, Toast.LENGTH_SHORT).show();
}
}
这里是Palyer.java
public class Player extends AppCompatActivity implements View.OnClickListener{
static MediaPlayer mp;
ArrayList mySongs;
int position;
Uri u;
Thread updateSeekBar;
SeekBar sb;
Button btPlay, btFF, btFB, btPv, btNxt;
MediaPlayer mediaPlayer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_player);
btPlay = (Button)findViewById(R.id.btPlay);
btFF = (Button)findViewById(R.id.btFF);
btFB = (Button)findViewById(R.id.btFB);
btPv = (Button)findViewById(R.id.btPv);
btNxt = (Button)findViewById(R.id.btNxt);
btPlay.setOnClickListener(this);
btFF.setOnClickListener(this);
btFB.setOnClickListener(this);
btPv.setOnClickListener(this);
btNxt.setOnClickListener(this);
sb = (SeekBar)findViewById(R.id.seekBar);
updateSeekBar = new Thread(){
@Override
public void run() {
//super.run();
int totalDuration = mp.getDuration();
int currentPosition = 0;
sb.setMax(totalDuration);
while(currentPosition<totalDuration){
try{
sleep(500);
currentPosition= mp.getCurrentPosition();
sb.setProgress(currentPosition);
} catch(InterruptedException e){
e.printStackTrace();
}
}
}
};
if(mp!=null){
mp.stop();
mp.release();
}
Intent i = getIntent();
mySongs.add(i.getStringExtra("songList"));
position=i.getIntExtra("pos",0);
u = Uri.parse(mySongs.get(position).toString());
mp = MediaPlayer.create(getApplicationContext(),u );
mp.release();
mp.prepareAsync();
mp.start();
sb.setMax(mp.getDuration());
updateSeekBar.start();
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean b) {
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
mp.seekTo(seekBar.getProgress());
}
});
}
@Override
public void onClick(View view) {
int id = view.getId();
switch (id){
case R.id.btPlay:
if(mp.isPlaying()){
btPlay.setText(">");
mp.pause();
}
else{
mp.start();
btPlay.setText("||");
}
break;
case R.id.btFF:
mp.seekTo(mp.getCurrentPosition()+5000);
break;
case R.id.btFB:
mp.seekTo(mp.getCurrentPosition()-5000);
break;
case R.id.btNxt:
mp.stop();
mp.release();
position = (position+1)%mySongs.size();
u = Uri.parse(mySongs.get(position).toString());
mp = MediaPlayer.create(getApplicationContext(),u );
mp.start();
sb.setMax(mp.getDuration());
break;
case R.id.btPv:
mp.stop();
mp.release();
position = (position-1<0)? mySongs.size()-1: position-1;
/*if(position-1<0){
position = mySongs.size()-1;
}
else{
position = position-1;
}*/
u = Uri.parse(mySongs.get(position).toString());
mp = MediaPlayer.create(getApplicationContext(),u );
mp.start();
sb.setMax(mp.getDuration());
break;
}
}
}
当我启动应用程序并单击 ListView 中的歌曲时，我的应用程序崩溃了，任何人都可以帮助从项目单击监听器中的 ListView 中获取歌曲吗 谢谢。
最佳答案
Make your songs arraylist serializable as:
public class SongsList implements Serializable
/// getter and setter
From Songs Files add object to SongList class then send this class
as:
Intent intent = new Intent(SourceActivity.this,
argetActivity.class);
intent.putExtra("SongListExtra", songList);
On receiving activity:
ArrayList<SongList> songlist = new ArrayList<SongList>();
songlist = (ArrayList<SongList>)
getIntent().getSerializableExtra("SongListExtra");
Instead of sending songList to player activity you can send that
particular song details on list item clicked according to position.
Hope it helps..
关于java - 如何在android中的项目单击中从 ListView 中获取歌曲，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44030299/