android 开发 W/TextToSpeech: speak failed: not bound to TTS engine

问题

笔者使用TTS(TextToSpeech)对于文本内容进行语音播报，控制台报错

android 开发 speak failed:not bound to TTS engine

详细问题

笔者核心代码：

import android.os.Bundle;
import android.speech.tts.TextToSpeech;
import android.speech.tts.TextToSpeech.OnInitListener;
import android.util.Log;
import android.view.View;import androidx.appcompat.app.AppCompatActivity;import com.google.android.material.floatingactionbutton.FloatingActionButton;import java.util.Locale;public class LoginActivity extends AppCompatActivity implements OnInitListener {private FloatingActionButton speakButton;private TextToSpeech textToSpeech;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_login);// 初始化TextToSpeech引擎textToSpeech = new TextToSpeech(this, this);// 找到按钮speakButton = findViewById(R.id.speakButton);// 设置按钮点击事件speakButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {// 在这里添加进行语音播报的代码speakOut("Your text to be spoken");}});}// 初始化TextToSpeech引擎的回调@Overridepublic void onInit(int status) {if (status == TextToSpeech.SUCCESS) {// 设置语音引擎的语言，例如英语int result = textToSpeech.setLanguage(Locale.ENGLISH);if (result == TextToSpeech.LANG_MISSING_DATA ||result == TextToSpeech.LANG_NOT_SUPPORTED) {Log.e("TTS", "Language is not supported.");}} else {Log.e("TTS", "Initialization failed.");}}// 进行语音播报的方法private void speakOut(String text) {textToSpeech.speak(text, TextToSpeech.QUEUE_FLUSH, null, null);}// 在Activity销毁时释放TextToSpeech引擎@Overrideprotected void onDestroy() {if (textToSpeech != null) {textToSpeech.stop();textToSpeech.shutdown();}super.onDestroy();}
}

运行控制台报错内容：

W/TextToSpeech: speak failed: not bound to TTS engine

解决方案

步骤1、在package\app\src\main\AndroidManifest.xml中配置如下内容：
具体操作如下图所示：
在这里插入图片描述
具体代码：

<queries><intent><action android:name="android.intent.action.TTS_SERVICE"/></intent>
</queries>

若进行英语播报，进行到此处问题即可解决。若是需要进行中文播报，需继续，进行步骤2的配置。

步骤2、修改上述代码：
尤其为onInit函数中代码内容：

	// 初始化TextToSpeech引擎的回调@Overridepublic void onInit(int status) {if (status == TextToSpeech.SUCCESS) {int result = textToSpeech.setLanguage(Locale.CHINESE);if (result == TextToSpeech.LANG_MISSING_DATA ||result == TextToSpeech.LANG_NOT_SUPPORTED) {Log.e("TTS", "不支持中文语音合成。");if (result == TextToSpeech.LANG_MISSING_DATA) {Log.e("TTS", "缺少中文语音数据，正在下载...");Intent installIntent = new Intent();installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);startActivity(installIntent);}} else {// 检查语音数据是否已下载if (textToSpeech.isLanguageAvailable(Locale.CHINESE) >= TextToSpeech.LANG_AVAILABLE) {Log.i("中文语音数据已完整下载");speakOut("打开该页面语音播报内容");paused = false; // 在初始化完成后将paused设置为false} else {Log.e("TTS", "中文语音数据未完整下载。");}}} else {Log.e("TTS", "TextToSpeech引擎初始化失败。");}}

完整代码：

import android.content.Context;
import android.content.Intent;
import android.media.AudioManager;
import android.os.Bundle;
import android.speech.tts.TextToSpeech;
import android.util.Log;
import android.view.View;import androidx.appcompat.app.AppCompatActivity;import com.google.android.material.floatingactionbutton.FloatingActionButton;import java.util.Locale;
public class LoginActivity extends AppCompatActivity implements TextToSpeech.OnInitListener {private FloatingActionButton speakButton;private TextToSpeech textToSpeech;private boolean paused = true; // Initialize paused to true@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_login);// 请求音频焦点AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);int result = audioManager.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {Log.i("TTS", "Audio focus requested successfully.");} else {Log.e("TTS", "Failed to request audio focus.");}// 初始化TextToSpeech引擎textToSpeech = new TextToSpeech(this, this);// 找到按钮speakButton = findViewById(R.id.speakButton);// 设置按钮点击事件speakButton.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {System.out.println("点击按钮");// Do nothing if pausedif (paused) {return;}// 在这里添加进行语音播报的代码speakOut("点击按钮语音播报内容");}});}// 初始化TextToSpeech引擎的回调@Overridepublic void onInit(int status) {if (status == TextToSpeech.SUCCESS) {int result = textToSpeech.setLanguage(Locale.CHINESE);if (result == TextToSpeech.LANG_MISSING_DATA ||result == TextToSpeech.LANG_NOT_SUPPORTED) {Log.e("TTS", "不支持中文语音合成。");if (result == TextToSpeech.LANG_MISSING_DATA) {Log.e("TTS", "缺少中文语音数据，正在下载...");Intent installIntent = new Intent();installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);startActivity(installIntent);}} else {// 检查语音数据是否已下载if (textToSpeech.isLanguageAvailable(Locale.CHINESE) >= TextToSpeech.LANG_AVAILABLE) {Log.i("TTS", "中文语音数据已完整下载");speakOut("打开该页面语音播报内容");paused = false; // 在初始化完成后将paused设置为false} else {Log.e("TTS", "中文语音数据未完整下载。");}}} else {Log.e("TTS", "TextToSpeech引擎初始化失败。");}}// 进行语音播报的方法private void speakOut(String text) {textToSpeech.speak(text, TextToSpeech.QUEUE_FLUSH, null, null);}// 在Activity销毁时释放TextToSpeech引擎@Overrideprotected void onDestroy() {if (textToSpeech != null) {textToSpeech.stop();textToSpeech.shutdown();}super.onDestroy();}
}

产生原因

按照官方文档要求，在Android11需要在manifest里声明TTS_SERVICE，以开启（英文）语音播报服务，而笔者的AndroidManifest.xml中缺少对TTS服务的配置。
（中文）语音数据未完整下载：在笔者的代码中，由于涉及对中文语音播报服务。如果中文语音数据未完整下载，也将导致TTS引擎可能无法正确工作。

解决原因

具体来说，以下是问题解决的原因：

步骤1、通过在AndroidManifest.xml中添加TTS服务的查询，可以确保应用可以与TTS引擎正确通信。

步骤2.1、
中文语音数据未完整下载：在onInit方法中，通过判断result是否等于TextToSpeech.LANG_MISSING_DATA来检测语音数据是否完整。如果数据不完整，会触发语音数据下载的操作。

if (result == TextToSpeech.LANG_MISSING_DATA) {Log.e("TTS", "缺少中文语音数据，正在下载...");Intent installIntent = new Intent();installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);startActivity(installIntent);
}

通过执行上述代码块，程序尝试在语音数据不完整时触发下载。

步骤2.2
设置语言为中文：通过

textToSpeech.setLanguage(Locale.CHINESE)

将语音引擎的语言设置为中文。

int result = textToSpeech.setLanguage(Locale.CHINESE);

确保了TTS引擎使用中文语音数据进行合成。

步骤2.3
检查语音数据是否已完整下载：通过检查语音数据是否已完整下载，以确保语音引擎能够正常使用。

if (textToSpeech.isLanguageAvailable(Locale.CHINESE) >= TextToSpeech.LANG_AVAILABLE) {Log.i("TTS", "中文语音数据已完整下载");speakOut("打开该页面语音播报内容");paused = false;
} else {Log.e("TTS", "中文语音数据未完整下载。");
}