【发布时间】：2017-04-28 08:28:31
【问题描述】：
我需要在我的应用程序中将我的SeekBar 与我的MediaPlayer 连接起来。
我通过 xml 设置了 SeekBar，如下所示：
<SeekBar
android:id="@+id/song_seekbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"/>
并按照这个SO answer 来实现它。
这是我的代码：
public class Song_main extends AppCompatActivity {
private final int SONG_REQUEST_CODE = 1;
private Uri song;
private TextView selectSong;
private SeekBar seekBar;
private Handler handler;
private MediaPlayer mediaPlayer;
private boolean repeatPressedTwice = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.app_bar_song_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.song_main_toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowTitleEnabled(false);
seekBar = (SeekBar) findViewById(R.id.song_seekbar);
handler = new Handler();
notSelected();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.song, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.song_plus) {
Intent selectIntent = new Intent(Intent.ACTION_GET_CONTENT);
selectIntent.setType("audio/*");
startActivityForResult(selectIntent, SONG_REQUEST_CODE);
}
return true;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == SONG_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
if ((data != null) && (data.getData()!=null)) {
song = data.getData();
setup();
}
}
}
private void notSelected() {
selectSong = (TextView) findViewById(R.id.select_song_textview);
selectSong.setText(getResources().getString(R.string.song_not_selected));
}
public void onPlayButtonClicked(View v) {
ImageButton pb = (ImageButton) findViewById(R.id.song_play_button);
if (!mediaPlayer.isPlaying()) {
mediaPlayer.start();
pb.setImageResource(R.drawable.pause);
updateSeekBar();
} else {
mediaPlayer.pause();
pb.setImageResource(R.drawable.ic_play_arrow_white_24dp);
}
}
public void onControlsClicked(View v) {
if (v.getId() == R.id.fast_forward) {
int pos = mediaPlayer.getCurrentPosition();
pos += 1500;
mediaPlayer.seekTo(pos);
}
else if (v.getId() == R.id.fast_backward) {
int pos = mediaPlayer.getCurrentPosition();
pos -= 1500;
mediaPlayer.seekTo(pos);
}
else if (v.getId() == R.id.skip_backward) {
mediaPlayer.seekTo(0);
}
}
public void onRepeatClicked(View v) {
if (!repeatPressedTwice) {
// TODO: change visual color of repeat button
mediaPlayer.setLooping(true);
Toast.makeText(this, "repeat enabled", Toast.LENGTH_SHORT).show();
repeatPressedTwice = true;
} else {
mediaPlayer.setLooping(false);
}
}
private void setup() {
/* the song has been select setup the interface */
/* displays song name in title */
TextView titleView = (TextView) findViewById(R.id.song_appbar_title);
String songName;
ContentResolver contentResolver = this.getContentResolver();
Cursor cursor = contentResolver.query(song, null, null, null, null);
if (cursor != null && cursor.moveToFirst()) {
songName = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
titleView.setText(songName);
}
/* removes the notSelected String */
selectSong.setVisibility(View.GONE);
/* setup media player */
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
mediaPlayer.setDataSource(getApplicationContext(), song);
mediaPlayer.prepareAsync();
} catch (IOException e) {
Toast.makeText(this, "file not found", Toast.LENGTH_SHORT).show();
}
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
/* show media player layout */
RelativeLayout mpl = (RelativeLayout) findViewById(R.id.media_player_layout);
mpl.setVisibility(View.VISIBLE);
mediaPlayer.start();
ImageButton pb = (ImageButton) findViewById(R.id.song_play_button);
pb.setImageResource(R.drawable.pause);
}
});
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
ImageButton pb = (ImageButton) findViewById(R.id.song_play_button);
pb.setImageResource(R.drawable.ic_play_arrow_white_24dp);
}
});
seekBar = (SeekBar) findViewById(R.id.song_seekbar);
seekBar.setMax(mediaPlayer.getDuration());
updateSeekBar();
}
private void updateSeekBar() {
seekBar.setProgress(mediaPlayer.getCurrentPosition()/1000);
handler.postDelayed(runnable, 1000);
}
Runnable runnable = new Runnable() {
@Override
public void run() {
updateSeekBar();
}
};
@Override
public void onStop() {
super.onStop();
if (mediaPlayer!=null)
mediaPlayer.stop();
}
}
流程从onOptionsItemSelected方法开始。
seekBar 行为正确，每秒递增。现在的问题是它在歌曲结束之前就结束了。
我尝试添加
seekBar.setMax(mediaPlayer.getDuration());
在setup 方法中，但这会导致条形图根本不动。
【问题讨论】：
标签： java android xml media-player seekbar