我创建了一个闹钟应用程序，当你设置它时，它会播放你选择的声音并给你一条消息，说明闹钟的设置时间。
问题是，我从来没有发出声音。 我在这里缺少什么？编辑：对不起，这就是我的
这是MainActivity：
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener{
AlarmManager alarmManager;
private PendingIntent pending_intent;
private TimePicker alarmTimePicker;
private static MainActivity inst;
private TextView alarmTextView;
private AlarmReceiver alarm;
private Context context;
Spinner spinner;
int richard_quote = 0;
@TargetApi(Build.VERSION_CODES.M)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// alarmTimePicker = (TimePicker) findViewById(R.id.alarmTimePicker);
// alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
this.context = this;
//alarm = new AlarmReceiver();
alarmTextView = (TextView) findViewById(R.id.alarmText);
final Intent myIntent = new Intent(this.context, AlarmReceiver.class);
// Get the alarm manager service
alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
// set the alarm to the time that you picked
final Calendar calendar = Calendar.getInstance();
//calendar.add(Calendar.SECOND, 3);
alarmTimePicker = (TimePicker) findViewById(R.id.alarmTimePicker);
//spinner creation
Spinner spinner = (Spinner) findViewById(R.id.richard_spinner);
// Create an ArrayAdapter using the string array and a default spinner layout
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.dawkins_sounds, android.R.layout.simple_spinner_item);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
spinner.setAdapter(adapter);
// Spinner click listener
spinner.setOnItemSelectedListener(this);
myIntent.putExtra("extra", "yes");
myIntent.putExtra("quote id", String.valueOf(richard_quote));
pending_intent = PendingIntent.getBroadcast(MainActivity.this, 0, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
Button start_alarm= (Button) findViewById(R.id.start_alarm);
start_alarm.setOnClickListener(new View.OnClickListener() {
@TargetApi(Build.VERSION_CODES.M)
@Override
public void onClick(View v) {
calendar.set(Calendar.HOUR, alarmTimePicker.getHour());
calendar.set(Calendar.MINUTE, alarmTimePicker.getMinute());
calendar.set(Calendar.SECOND, 0);
// calendar.set(Calendar.HOUR_OF_DAY, alarmTimePicker.getHour());
// calendar.set(Calendar.MINUTE, alarmTimePicker.getMinute());
final int hour = alarmTimePicker.getHour();
final int minute = alarmTimePicker.getMinute();;
String minute_string = String.valueOf(minute);
String hour_string = String.valueOf(hour);
if (minute < 10) {
minute_string = "0" + String.valueOf(minute);
}
if (hour > 12) {
hour_string = String.valueOf(hour - 12) ;
}
// myIntent.putExtra("extra", "yes");
// myIntent.putExtra("quote id", String.valueOf(richard_quote));
// pending_intent = PendingIntent.getBroadcast(MainActivity.this, 0, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
// alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pending_intent);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pending_intent);
// setAlarmText("Alarm ON ");
setAlarmText("Alarm set to " + hour_string + ":" + minute_string);
}
});
Button stop_alarm= (Button) findViewById(R.id.stop_alarm);
stop_alarm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
myIntent.putExtra("extra", "no");
myIntent.putExtra("quote id", String.valueOf(richard_quote));
sendBroadcast(myIntent);
alarmManager.cancel(pending_intent);
setAlarmText("Alarm canceled");
//setAlarmText("ID is " + richard_quote);
}
});
}
public void setAlarmText(String alarmText) {
alarmTextView.setText(alarmText);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onStart() {
super.onStart();
inst = this;
}
@Override
public void onDestroy() {
super.onDestroy();
Log.e("MyActivity", "on Destroy");
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//Toast.makeText(parent.getContext(), "Spinner item 3!" + id, Toast.LENGTH_SHORT).show();
richard_quote = (int) id;
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// Another interface callback
}
}
这是AlarmReceiver
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String state = intent.getExtras().getString("extra");
Log.e("MyActivity", "In the receiver with " + state);
String richard_id = intent.getExtras().getString("quote id");
Log.e("Goat quote is" , richard_id);
Intent serviceIntent = new Intent(context,RingtonePlayingService.class);
serviceIntent.putExtra("extra", state);
serviceIntent.putExtra("quote id", richard_id);
context.startService(serviceIntent);
}
}
这是RingtonrPlayingService
public class RingtonePlayingService extends Service {
private boolean isRunning;
private Context context;
MediaPlayer mMediaPlayer;
private int startId;
@Override
public IBinder onBind(Intent intent)
{
Log.e("MyActivity", "In the alarm service");
return null;
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
final NotificationManager mNM = (NotificationManager)
getSystemService(NOTIFICATION_SERVICE);
Intent intent1 = new Intent(this.getApplicationContext(), MainActivity.class);
PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent1, 0);
Notification mNotify = new Notification.Builder(this)
.setContentTitle("alarm is talking" + "!")
.setContentText("Click me!")
.setSmallIcon(R.drawable.ic_action_call)
.setContentIntent(pIntent)
.setAutoCancel(true)
.build();
String state = intent.getExtras().getString("extra");
Log.e("what is going on here ", state);
assert state != null;
switch (state) {
case "no":
startId = 0;
break;
case "yes":
startId = 1;
break;
default:
startId = 0;
break;
}
// get richard's thing
String richard_id = intent.getExtras().getString("quote id");
Log.e("Service: goatid is " , richard_id);
if(!this.isRunning && startId == 1) {
Log.e("if there was not sound ", " and you want start");
assert richard_id != null;
if (richard_id.equals("0")) {
int min = 1;
int max = 2;
Random r = new Random();
int random_number = r.nextInt(max - min + 1) + min;
Log.e("random number is ", String.valueOf(random_number));
if (random_number == 1) {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm2);
}
else if (random_number == 2) {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm1);
}
else {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm2);
}
}
else if (richard_id.equals("1")) {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm2);
}
else if (richard_id.equals("2")) {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm1);
}
else {
mMediaPlayer = MediaPlayer.create(this, R.raw.alarm2;
}
mMediaPlayer.start();
mNM.notify(0, mNotify);
this.isRunning = true;
this.startId = 0;
}
else if (!this.isRunning && startId == 0){
Log.e("if there was not sound ", " and you want end");
this.isRunning = false;
this.startId = 0;
}
else if (this.isRunning && startId == 1){
Log.e("if there is sound ", " and you want start");
this.isRunning = true;
this.startId = 0;
}
else {
Log.e("if there is sound ", " and you want end");
mMediaPlayer.stop();
mMediaPlayer.reset();
this.isRunning = false;
this.startId = 0;
}
Log.e("MyActivity", "In the service");
return START_NOT_STICKY;
}
@Override
public void onDestroy() {
Log.e("JSLog", "on destroy called");
super.onDestroy();
this.isRunning = false;
}
}
答案 0 :(得分：0)
您没有正确启动MediaPlayer。
通读本文，特别是关于将MediaPlayer与服务一起使用的部分：
https://developer.android.com/guide/topics/media/mediaplayer.html
基本上，步骤是
您跳过了步骤2，步骤2需要一些工作才能在从服务进行播放时正常运行。您也没有正确管理MediaPlayer资源。
此处有更多详情：
https://developer.android.com/reference/android/media/MediaPlayer.html
具体说明（在页面顶部，刚好超过状态图）
MediaPlayer对象必须先进入Prepared状态 可以开始播放。