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我遇到了我的應用的音樂播放問題。我在一個可以在整個應用程序中播放音樂的服務類中設置媒體播放器。但是，我遇到的問題是將屏幕從「選項」頁面再次更改爲主頁。Android：保存音樂狀態（初學者）
在選項類中，我有一個單擊的ToggleButton，它可以在單擊時打開和關閉音樂，並且我使用布爾值來確定ToggleButton是否自動開啓和關閉，具體取決於音樂是否正在播放。
但是，當用戶點擊後退按鈕或保存按鈕（將它們發送回主頁時），即使音樂被選中爲「關閉」，音樂也會重新開始播放。
有人對我有什麼建議嗎？
服務類：
public class MyMusicService extends Service {
MediaPlayer mp;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mp = MediaPlayer.create(this, R.raw.song);
mp.start();
mp.setLooping(true);
return super.onStartCommand(intent, flags, startId);
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onDestroy() {
super.onDestroy();
if(mp!=null) {
mp.stop();
mp.release();
}
mp=null;
}
}
選項類別：
public class OptionsActivity extends Activity {
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Intent i = new Intent(OptionsActivity.this, MainActivity.class);
startActivity(i);
return true;
}
return super.onKeyDown(keyCode, event);
}
private boolean isMyServiceRunning(String serviceCanonicalClassName) {
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (serviceCanonicalClassName.equals(service.service.getClassName())) {
return true;
}
}
return false;
}
Intent i; // Handles MyMusicService.java
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.options);
final TextView tSound = (TextView) findViewById(R.id.textView2);
final Button saveBtn = (Button) findViewById(R.id.optSaveBtn);
final Button tblBtn = (Button) findViewById(R.id.tableBtn);
i=new Intent(this, MyMusicService.class);
final ToggleButton soundOption = (ToggleButton) findViewById(R.id.soundPref);
boolean musicPlays = isMyServiceRunning(MyMusicService.class.getCanonicalName());
soundOption.setChecked(musicPlays);
if(musicPlays==true){
tSound.setText("On");
}
if(musicPlays==false) {
tSound.setText("Off");
}
soundOption.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on clicks to control sound being on and off.
if(soundOption.isChecked()) {
Toast.makeText(OptionsActivity.this, "Music on.", Toast.LENGTH_SHORT).show();
startService(i);
Intent i = new Intent(OptionsActivity.this, OptionsActivity.class);
startActivity(i);
}
else {
if(stopService(i)==true){
soundOption.setChecked(false);
stopService(i);
Toast.makeText(OptionsActivity.this, "Music off.", Toast.LENGTH_SHORT).show();
Intent i = new Intent(OptionsActivity.this, OptionsActivity.class);
startActivity(i);
}
}
}
});
tblBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent tblView = new Intent(OptionsActivity.this, SQLView.class);
startActivity(tblView);
}
});
saveBtn.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
Intent homePage = new Intent(OptionsActivity.this, MainActivity.class);
switch (v.getId()){
case R.id.optSaveBtn: //Determine what will happen when the user presses the "Submit button".
boolean optionsWork = true;
try{
String sound = tSound.getText().toString();
optionsDB entry = new optionsDB(OptionsActivity.this); //Creating a new instance of MasterMind game
entry.open();
entry.createOptionEntry(sound); //Passing both strings
entry.close();
}catch (Exception e){ //Creating an error message if for some reason the app cannot transfer data to the Database.
Toast.makeText(OptionsActivity.this, "Error", Toast.LENGTH_SHORT).show();
}
finally { //Creating an AlertDialog box when the user presses the Submit button.
if (optionsWork){
Toast.makeText(OptionsActivity.this, "Settings Saved", Toast.LENGTH_SHORT).show();
}
}
break;
}
startActivity(homePage);
}
});
}
}
最後，家居類：
public class MainActivity extends Activity {
Intent i;
private boolean isMyServiceRunning(String serviceCanonicalClassName) {
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
if (serviceCanonicalClassName.equals(service.service.getClassName())) {
return true;
}
}
return false;
}
public void checkSound(){
boolean musicPlays = isMyServiceRunning(MyMusicService.class.getCanonicalName());
if(musicPlays==true){
//Do nothing
}
else {
stopService(i);
}
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//setting the layout
//Start Networking
//Intent net = new Intent(this, Networking.class);
//startService(net);
//Auto starts playing music on app launch.
i = new Intent(this,MyMusicService.class);
startService(i);
checkSound();
final ImageView findGame = (ImageView) findViewById(R.id.btnFindGame);
final ImageView profile = (ImageView) findViewById(R.id.btnProfile);
final ImageView instructions = (ImageView) findViewById(R.id.btnInstructions);
final ImageView options = (ImageView) findViewById(R.id.btnOptions);
findGame.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, DrawActivity.class);
startActivity(intent);
}
});
profile.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, WaitingActivity.class);
startActivity(intent);
}
});
instructions.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, InstructionsActivity.class);
startActivity(intent);
}
});
options.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, OptionsActivity.class);
startActivity(intent);
}
});
}
//On app close, music stops playing.
@Override
protected void onDestroy() {
if (this.isFinishing()){
super.onDestroy();
stopService(i);
//finish();
}
}
}
任何幫助將是非常讚賞，謝謝。
您好，謝謝爲了您的評論。 我不認爲你可以告訴我一個這樣的例子嗎？我一直在努力嘗試，並遇到一些問題。要麼它沒有播放或代碼中的錯誤。 – 2012-03-27 16:17:28