【发布时间】:2012-07-31 11:48:18
【问题描述】:
我的 android 应用程序具有文本朗读功能,并且不止一个活动使用此功能。因此创建了一个静态帮助器类来简化此操作。
import java.util.Locale;
import android.content.Context;
import android.speech.tts.TextToSpeech;
import android.speech.tts.TextToSpeech.OnInitListener;
import android.util.Log;
public class TextToSpeechController implements OnInitListener {
private static final String TAG = "TextToSpeechController";
private TextToSpeech myTTS;
private String textToSpeak;
private Context context;
private static TextToSpeechController singleton;
public static TextToSpeechController getInstance(Context ctx) {
if (singleton == null)
singleton = new TextToSpeechController(ctx);
return singleton;
}
private TextToSpeechController(Context ctx) {
context = ctx;
}
public void speak(String text) {
textToSpeak = text;
if (myTTS == null) {
// currently can't change Locale until speech ends
try {
// Initialize text-to-speech. This is an asynchronous operation.
// The OnInitListener (second argument) is called after
// initialization completes.
myTTS = new TextToSpeech(context, this);
} catch (Exception e) {
e.printStackTrace();
}
}
sayText();
}
public void onInit(int initStatus) {
if (initStatus == TextToSpeech.SUCCESS) {
if (myTTS.isLanguageAvailable(Locale.UK) == TextToSpeech.LANG_AVAILABLE)
myTTS.setLanguage(Locale.UK);
}
// status can be either TextToSpeech.SUCCESS or TextToSpeech.ERROR.
if (initStatus == TextToSpeech.SUCCESS) {
int result = myTTS.setLanguage(Locale.UK);
if (result == TextToSpeech.LANG_MISSING_DATA
|| result == TextToSpeech.LANG_NOT_SUPPORTED) {
Log.e(TAG, "TTS missing or not supported (" + result + ")");
// Language data is missing or the language is not supported.
// showError(R.string.tts_lang_not_available);
} else {
// Initialization failed.
Log.e(TAG, "Error occured");
}
}
}
private void sayText() {
// ask TTs to say the text
myTTS.speak(this.textToSpeak, TextToSpeech.QUEUE_FLUSH, null);
}
public void stopTTS() {
if (myTTS != null) {
myTTS.shutdown();
myTTS.stop();
myTTS = null;
}
}
}
我正在像这样使用这个助手类。
TextToSpeechController.getInstance(this).speak(readableMessage);
但有时我会在 LogCat 上看到如下行之类的错误。
"speak:failed not bound to tts engine"
没有抛出异常,但 TTS 没有读取任何内容。 我意识到如果我从 BroadcastReceiver 触发活动,我会收到此错误。否则,如果从应用程序代码手动打开活动没有问题。
这是广播接收器代码
private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String newMessage = intent.getExtras().getString(EXTRA_MESSAGE);
String readableMessage = intent.getExtras().getString(READABLE_MESSAGE);
Bundle b = new Bundle();
b.putString(EXTRA_MESSAGE, newMessage);
b.putString(READABLE_MESSAGE, readableMessage);
Intent newIntent = new Intent("android.intent.action.MAIN");
newIntent.setClass(context, Speak.class);
newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
newIntent.putExtra("MessageReceived", b);
newIntent.putExtra("CallType", CallType.NOTIFICATION);
context.startActivity(newIntent);
}
};
【问题讨论】: