我正在处理一个简单的媒体播放器并遇到问题。当我尝试使用setVolume时，它只在设置为1.0,1.0时有效/有声。如果它将其设置为其他任何东西（例如1.0,0.8; 1.0,0.0; 0.5,1.0;等等），它将完全静音。我在Nexus 6（7.0）上进行测试，如果这有任何区别的话。
我已经尝试将setVolume放在几个不同的地方，想想它可能会有一些效果，但似乎没有什么能改变它的行为。我也试过取出setVolumeControlStream（AudioManager.STREAM_MUSIC）;认为它弄乱了一些事情，但没有改变。
我最终的目标是让声音播放在右边，然后是左边，然后是右边，然后是左边，等等来回弹跳（特定的奇怪应用），所以我需要独立调整每侧的音量相当多。
编辑：能够在朋友的手机（运行6.0.1的Galaxy S5）上进行测试，并且它与相同的代码完美配合。想法？谢谢！
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SeekBar;
import android.widget.Toast;
import java.util.IllegalFormatException;
public class MainActivity extends Activity {
// variable declaration
private ListView mainList;
private MediaPlayer mp;
private final String[] listContent = { "Adele", "Moana", "Wanna be Balla", "Move Bitch", "Linkin Park"};
private Button playMusic;
private final int[] resID = { R.raw.adele, R.raw.moana, R.raw.balla, R.raw.ludacris, R.raw.linkinpark};
long startTime;
public volatile Integer i;
private SeekBar duration;
public Integer p;
private static String tag = "EMDR Player is";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Layout thingies
duration = (SeekBar) findViewById(R.id.duration);
playMusic = (Button) findViewById(R.id.playButton);
setVolumeControlStream(AudioManager.STREAM_MUSIC);
i = 0;
p = 0;
// Initializing variables
mainList = (ListView) findViewById(R.id.listView1);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, listContent);
mainList.setAdapter(adapter);
mp = new MediaPlayer();
mp.setLooping(true);
duration.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){
@Override
public void onProgressChanged(SeekBar duration, int progress,
boolean fromUser) {
p = progress;
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
// final Integer sleeptime = 1000;
/* t = new Thread(new Runnable() {
@Override
public void run(){
while (i == 0) {
try {
mp.setVolume(1.0f, 1.0f);
Thread.sleep(sleeptime);
mp.setVolume(0.0f, 0.0f);
Thread.sleep(sleeptime);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});*/
mainList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view,
int position, long id) {
playSong(position);
}
});
mp.setOnErrorListener(new MediaPlayer.OnErrorListener() {
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
Log.d(tag, "is onError()");
switch(what){
case MediaPlayer.MEDIA_ERROR_UNKNOWN:
// handle MEDIA_ERROR_UNKNOWN, optionally handle extras
handleExtras(extra);
break;
case MediaPlayer.MEDIA_ERROR_SERVER_DIED:
// handle MEDIA_ERROR_SERVER_DIED, optionally handle extras
handleExtras(extra);
break;
}
return true;
}
});
playMusic.setOnClickListener(new View.OnClickListener(){
// creates a new onclick listener (does a thing when it's clicked) for our button "playMusic"
@Override
public void onClick(View v){
if (mp.isPlaying()) {
pauseMusic(); // runs the pauseMusic method
i = 1;
Toast.makeText(getApplicationContext(), "Elapsed time was " + ((startTime)/1000) + " seconds.", Toast.LENGTH_SHORT).show();
Log.d(tag, "is Pause Clicked()");
}
else {
resettobeginningMusic(); // starts the music from the beginning
startMusic(); // runs the startMusic method
i = 0;
Log.d(tag, "is Start Clicked()");
//toast();
}
}
});}
public void playSong(int songIndex) {
try{
mp.reset();// stops any current playing song
i = 0;
mp = MediaPlayer.create(getApplicationContext(), resID[songIndex]);
playMusic.setText(getString(R.string.button_pause));
final int test = p;
final Thread thread = new Thread(new MyRunnable(test));
thread.start();
Toast.makeText(getApplicationContext(), "Elapsed time was " + ((test)/1000) + " seconds.", Toast.LENGTH_SHORT).show();
mp.start();
Log.d(tag, "is Initially Started()");
} catch (IllegalStateException | IllegalFormatException e){
e.printStackTrace();
}
}
public void pauseMusic(){
try{
if (mp !=null){
mp.pause();
startTime=mp.getCurrentPosition();
playMusic.setText(getString(R.string.button_start));
i = 1;
Log.d(tag, "is Paused()");
}
} catch (IllegalStateException | IllegalFormatException e){
e.printStackTrace();
}
}
public void startMusic(){
try{
if (mp != null) {
i = 0;
playMusic.setText(getString(R.string.button_pause));
final int test = p;
final Thread thread = new Thread(new MyRunnable(test));
thread.start();
Toast.makeText(getApplicationContext(), "Elapsed time was " + ((test) / 1000) + " seconds.", Toast.LENGTH_SHORT).show();
mp.start();
Log.d(tag, "is Started()");
}
} catch (IllegalStateException | IllegalFormatException e){
e.printStackTrace();
}
}
public class MyRunnable implements Runnable {
protected Integer mFoo;
public MyRunnable(Integer foo) {
mFoo = foo;
}
public void run() {while (i == 0) {
try {
mp.setVolume(1.0f, 0.0f);
Thread.sleep(mFoo);
mp.setVolume(0.0f, 1.0f);
Thread.sleep(mFoo);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}}
public void resettobeginningMusic() {
try{
if (mp != null) {
mp.seekTo(0);
Log.d(tag, "is Resetting()");
}
} catch (IllegalStateException | IllegalFormatException e){
e.printStackTrace();
}
}
private void handleExtras(int extra){
switch(extra){
case MediaPlayer.MEDIA_ERROR_IO:
// handle MEDIA_ERROR_IO
break;
case MediaPlayer.MEDIA_ERROR_MALFORMED:
// handle MEDIA_ERROR_MALFORMED
break;
case MediaPlayer.MEDIA_ERROR_UNSUPPORTED:
// handle MEDIA_ERROR_UNSPECIFIED
break;
case MediaPlayer.MEDIA_ERROR_TIMED_OUT:
// handle MEDIA_ERROR_TIMED_OUT
break;
}
}
protected void onDestroy(){
if (mp !=null && mp.isPlaying()) {
mp.stop();
mp.release();
mp = null;
}
super.onDestroy();
}
}