android 中TextToSpeech的用法

時間 2019-11-06

標籤 android texttospeech 用法欄目 Android 简体版

原文原文鏈接

目前只支持5種語言，分別是English、 French 、 German 、 Italian 和 Spanish.java

系統要求爲android 1.6以上android

直接上代碼啦：ios

[java] web

public class TTSActivity extends Activity implements TextToSpeech.OnInitListener { app
private static final String TAG = "TextToSpeechDemo"; ide

private TextToSpeech mTts;//首先來個對象，至於TextToSpeech類，按F3能夠查看函數

[java] oop

//TODO complete javadoc + add links to constants 學習
public class TextToSpeech { ui
/**
* Denotes a successful operation.
*/
public static final int SUCCESS = 0;
/**
* Denotes a generic operation failure.
*/
public static final int ERROR = -1;

以上只包含部分代碼，其餘的就省略了。

[java]

mTts = new TextToSpeech(this,
this // TextToSpeech.OnInitListener
);

而後是實例化，構造函數參數也能夠F3一下

[java]

public TextToSpeech(Context context, OnInitListener listener) {
mContext = context;
mPackageName = mContext.getPackageName();
mInitListener = listener;
mCachedParams = new String[2*Engine.NB_CACHED_PARAMS]; // store key and value
mCachedParams[Engine.PARAM_POSITION_RATE] = Engine.KEY_PARAM_RATE;
mCachedParams[Engine.PARAM_POSITION_LANGUAGE] = Engine.KEY_PARAM_LANGUAGE;
mCachedParams[Engine.PARAM_POSITION_COUNTRY] = Engine.KEY_PARAM_COUNTRY;
mCachedParams[Engine.PARAM_POSITION_VARIANT] = Engine.KEY_PARAM_VARIANT;
mCachedParams[Engine.PARAM_POSITION_STREAM] = Engine.KEY_PARAM_STREAM;
mCachedParams[Engine.PARAM_POSITION_UTTERANCE_ID] = Engine.KEY_PARAM_UTTERANCE_ID;
mCachedParams[Engine.PARAM_POSITION_RATE + 1] =
String.valueOf(Engine.DEFAULT_RATE);
// initialize the language cached parameters with the current Locale
Locale defaultLoc = Locale.getDefault();
mCachedParams[Engine.PARAM_POSITION_LANGUAGE + 1] = defaultLoc.getISO3Language();
mCachedParams[Engine.PARAM_POSITION_COUNTRY + 1] = defaultLoc.getISO3Country();
mCachedParams[Engine.PARAM_POSITION_VARIANT + 1] = defaultLoc.getVariant();
mCachedParams[Engine.PARAM_POSITION_STREAM + 1] =
String.valueOf(Engine.DEFAULT_STREAM);
mCachedParams[Engine.PARAM_POSITION_UTTERANCE_ID + 1] = "";
initTts();
}

context也就是那個Activity

[java]

public abstract class Context {
/**
* File creation mode: the default mode, where the created file can only
* be accessed by the calling application (or all applications sharing the
* same user ID).
* @see #MODE_WORLD_READABLE
* @see #MODE_WORLD_WRITEABLE
*/
public static final int MODE_PRIVATE = 0x0000;
/**
* File creation mode: allow all other applications to have read access
* to the created file.
* @see #MODE_PRIVATE
* @see #MODE_WORLD_WRITEABLE
*/
public static final int MODE_WORLD_READABLE = 0x0001;
/**
* File creation mode: allow all other applications to have write access
* to the created file.
* @see #MODE_PRIVATE
* @see #MODE_WORLD_READABLE
*/

listener是個初始化監聽接口

[java]

/**
* Called when the TTS has initialized.
*
* The InitListener must implement the onInit function. onInit is passed a
* status code indicating the result of the TTS initialization.
*/
public interface OnInitListener {
public void onInit(int status);
}

implements Listener代碼以下：(這是APIDemo裏面的)

[java]

// Implements TextToSpeech.OnInitListener.
public void onInit(int status) {
// status can be either TextToSpeech.SUCCESS or TextToSpeech.ERROR.
if (status == TextToSpeech.SUCCESS) {
// Set preferred language to US english.
// Note that a language may not be available, and the result will indicate this.
int result = mTts.setLanguage(Locale.US);
// Try this someday for some interesting results.
// int result mTts.setLanguage(Locale.FRANCE);
if (result == TextToSpeech.LANG_MISSING_DATA ||
result == TextToSpeech.LANG_NOT_SUPPORTED) {
// Lanuage data is missing or the language is not supported.
Log.e(TAG, "Language is not available.");
} else {
// Check the documentation for other possible result codes.
// For example, the language may be available for the locale,
// but not for the specified country and variant.
// The TTS engine has been successfully initialized.
// Allow the user to press the button for the app to speak again.
mAgainButton.setEnabled(true);
// Greet the user.
sayHello();
}
} else {
// Initialization failed.
Log.e(TAG, "Could not initialize TextToSpeech.");
}
}

status這個在構造函數中賦值，(Ctrl+F能夠在源碼中找到)

[java]

mCachedParams[Engine.PARAM_POSITION_STREAM + 1] =
String.valueOf(Engine.DEFAULT_STREAM);
mCachedParams[Engine.PARAM_POSITION_UTTERANCE_ID + 1] = "";
initTts();//構造函數最後這個地方
}
private void initTts() {
mStarted = false;
// Initialize the TTS, run the callback after the binding is successful
mServiceConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName name, IBinder service) {
synchronized(mStartLock) {
mITts = ITts.Stub.asInterface(service);
mStarted = true;
if (mInitListener != null) {
// TODO manage failures and missing resources
mInitListener.onInit(SUCCESS);//這裏給status賦值
}
}
}

setLanguage方法源碼：

[java]

public int setLanguage(Locale loc) {
synchronized (mStartLock) {
int result = LANG_NOT_SUPPORTED;
if (!mStarted) {
return result;
}
try {
mCachedParams[Engine.PARAM_POSITION_LANGUAGE + 1] = loc.getISO3Language();
mCachedParams[Engine.PARAM_POSITION_COUNTRY + 1] = loc.getISO3Country();
mCachedParams[Engine.PARAM_POSITION_VARIANT + 1] = loc.getVariant();
// the language is not set here, instead it is cached so it will be associated
// with all upcoming utterances. But we still need to report the language support,
// which is achieved by calling isLanguageAvailable()
result = mITts.isLanguageAvailable(
mCachedParams[Engine.PARAM_POSITION_LANGUAGE + 1],
mCachedParams[Engine.PARAM_POSITION_COUNTRY + 1],
mCachedParams[Engine.PARAM_POSITION_VARIANT + 1] );
} catch (RemoteException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - setLanguage", "RemoteException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (NullPointerException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - setLanguage", "NullPointerException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (IllegalStateException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - setLanguage", "IllegalStateException");
e.printStackTrace();
mStarted = false;
initTts();
} finally {
return result;
}
}
}

Locale.US定義以下:

[java]

public static final Locale UK = new Locale("en", "GB"); //$NON-NLS-1$ //$NON-NLS-2$
/**
* Locale constant for en_US.
*
* @since Android 1.0
*/
public static final Locale US = new Locale("en", "US"); //$NON-NLS-1$//$NON-NLS-2$

Locale構造器源碼:

[java] view plain copy

/**
* Constructs a new {@code Locale} using the specified language and country codes.
*
* @param language
* the language this {@code Locale} represents.
* @param country
* the country this {@code Locale} represents.
* @since Android 1.0
*/
public Locale(String language, String country) {
this(language, country, ""); //$NON-NLS-1$
}

這裏每按一次按鈕就有一個Speech

[java]

private void sayHello() {
String left = "Please turn left";
String right="Please turn right";
if(mDirection==0){
mTts.speak(left,
TextToSpeech.QUEUE_FLUSH, // Drop all pending entries in the playback queue.
null);
mDirection=1;
}else{
mTts.speak(right, TextToSpeech.QUEUE_FLUSH, null);
mDirection=0;
}

speak函數源碼:各參數都有相應的解釋，我就不囉嗦了

[java]

/**
* Speaks the string using the specified queuing strategy and speech
* parameters. Note that the speech parameters are not universally supported
* by all engines and will be treated as a hint. The TTS library will try to
* fulfill these parameters as much as possible, but there is no guarantee
* that the voice used will have the properties specified.
*
* @param text
* The string of text to be spoken.
* @param queueMode
* The queuing strategy to use.
* See QUEUE_ADD and QUEUE_FLUSH.
* @param params
* The hashmap of speech parameters to be used.
*
* @return Code indicating success or failure. See {@link #ERROR} and {@link #SUCCESS}.
*/
public int speak(String text, int queueMode, HashMap<String,String> params)
{
synchronized (mStartLock) {
int result = ERROR;
Log.i("TTS received: ", text);
if (!mStarted) {
return result;
}
try {
if ((params != null) && (!params.isEmpty())) {
String extra = params.get(Engine.KEY_PARAM_STREAM);
if (extra != null) {
mCachedParams[Engine.PARAM_POSITION_STREAM + 1] = extra;
}
extra = params.get(Engine.KEY_PARAM_UTTERANCE_ID);
if (extra != null) {
mCachedParams[Engine.PARAM_POSITION_UTTERANCE_ID + 1] = extra;
}
}
result = mITts.speak(mPackageName, text, queueMode, mCachedParams);
} catch (RemoteException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - speak", "RemoteException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (NullPointerException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - speak", "NullPointerException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (IllegalStateException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - speak", "IllegalStateException");
e.printStackTrace();
mStarted = false;
initTts();
} finally {
resetCachedParams();
return result;
}
}
}

還有在Activity退出時做一些操做

[java]

@Override
public void onDestroy() {
// Don't forget to shutdown!
if (mTts != null) {
mTts.stop();
mTts.shutdown();
}
super.onDestroy();
}

能看到源碼真好...深刻學習...呵呵

咱們再看下android 究竟是怎樣stop和shutdown的

[java] view plain copy

/**
* Stops speech from the TTS.
*
* @return Code indicating success or failure. See {@link #ERROR} and {@link #SUCCESS}.
*/
public int stop() {
synchronized (mStartLock) {
int result = ERROR;
if (!mStarted) {
return result;
}
try {
result = mITts.stop(mPackageName);
} catch (RemoteException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - stop", "RemoteException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (NullPointerException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - stop", "NullPointerException");
e.printStackTrace();
mStarted = false;
initTts();
} catch (IllegalStateException e) {
// TTS died; restart it.
Log.e("TextToSpeech.java - stop", "IllegalStateException");
e.printStackTrace();
mStarted = false;
initTts();
} finally {
return result;
}
}
}