TextToSpeech拋出一個未知的異常

Question

我正在創建一個涉及短信的android應用程序，其中一個功能是在輸入時讀出每個字母。我正在使用TextToSpeech。

我有它在一個測試項目工作但將其集成到我自己，當我收到未知異常。

任何人都可以看到什麼可能導致這種情況，並建議一種補救措施？我創建了一個叫做speech的類，它在另一個類中實例化，並且有一個調用方法（類似於下面的第二個例子）。任何人都可以解釋爲什麼我需要在第一個例子中擴展Activity嗎？同樣有問題的一行說「新TextToSpeech未定義」。

代碼無法工作。錯誤是tts = new TextToSpeech(this, this);

public class Speech extends Activity implements TextToSpeech.OnInitListener { 

    private TextToSpeech tts; 
    private String toRead; 

    public Speech(String toRead){ 

     this.toRead = toRead; 
     tts = new TextToSpeech(this, this); 
    } 

這裏是哪裏它的工作

public class MainActivity extends Activity implements 
     TextToSpeech.OnInitListener { 
    /** Called when the activity is first created. */ 

    private TextToSpeech tts; 
    private Button btnSpeak; 
    private EditText txtText; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     tts = new TextToSpeech(this, this); 

     btnSpeak = (Button) findViewById(R.id.btnSendSMS); 

     txtText = (EditText) findViewById(R.id.txtMessage); 

     // button on click event 
     btnSpeak.setOnClickListener(new View.OnClickListener() { 

      public void onClick(View arg0) { 
       speakOut(); 
      } 

     }); 
    } 

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

    public void onInit(int status) { 

     if (status == TextToSpeech.SUCCESS) { 

      int result = tts.setLanguage(Locale.US); 

      if (result == TextToSpeech.LANG_MISSING_DATA 
        || result == TextToSpeech.LANG_NOT_SUPPORTED) { 
       Log.e("TTS", "This Language is not supported"); 
      } else { 
       btnSpeak.setEnabled(true); 
       speakOut(); 
      } 

     } else { 
      Log.e("TTS", "Initilization Failed!"); 
     } 

    } 

    private void speakOut() { 

     String text = txtText.getText().toString(); 

     tts.speak(text, TextToSpeech.QUEUE_FLUSH, null); 
    } 
} 

logcat的信息

02-13 20:00:54.974: D/AndroidRuntime(11127): Shutting down VM 
02-13 20:00:54.974: W/dalvikvm(11127): threadid=1: thread exiting with uncaught exception (group=0x411cd300) 
02-13 20:00:54.979: E/AndroidRuntime(11127): FATAL EXCEPTION: main 
02-13 20:00:54.979: E/AndroidRuntime(11127): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.BT/org.BT.Text_entry}: java.lang.NullPointerException 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2024) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread.access$600(ActivityThread.java:140) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.os.Handler.dispatchMessage(Handler.java:99) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.os.Looper.loop(Looper.java:137) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread.main(ActivityThread.java:4898) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at java.lang.reflect.Method.invokeNative(Native Method) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at java.lang.reflect.Method.invoke(Method.java:511) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at dalvik.system.NativeStart.main(Native Method) 
02-13 20:00:54.979: E/AndroidRuntime(11127): Caused by: java.lang.NullPointerException 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.content.ContextWrapper.getContentResolver(ContextWrapper.java:91) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TtsEngines.getDefaultEngine(TtsEngines.java:75) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TextToSpeech.getDefaultEngine(TextToSpeech.java:1235) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TextToSpeech.initTts(TextToSpeech.java:595) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:553) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:527) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.speech.tts.TextToSpeech.<init>(TextToSpeech.java:512) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at org.BT.Speech.<init>(Speech.java:17) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at org.BT.Text_entry.<init>(Text_entry.java:48) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at java.lang.Class.newInstanceImpl(Native Method) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at java.lang.Class.newInstance(Class.java:1319) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.Instrumentation.newActivity(Instrumentation.java:1057) 
02-13 20:00:54.979: E/AndroidRuntime(11127): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2015) 
02-13 20:00:54.979: E/AndroidRuntime(11127): ... 11 more 

代碼-------------- - - - - - - - - - - - - - -編輯 - - - - - - - - - - - --------------------------------- 進一步的研究表明，這可能是因爲我試圖在Android框架之外一個Android上下文？這可能是真的 - 因爲我正在使用一個類而不是一個活動？如果是的話，我會怎樣解決這個問題？

Answer 1

這就是我要做的事..

public class TextToSpeechActivity extends Activity implements TextToSpeech.OnInitListener 
{ 
private TextToSpeech mTts; 
// This code can be any value you want, its just a checksum. 
private static final int MY_DATA_CHECK_CODE = 1234; 

/** 
* Called when the activity is first created. 
*/ 
@Override 
public void onCreate(Bundle savedInstanceState) 
{ 
super.onCreate(savedInstanceState); 
setContentView(R.layout.main); 

// Fire off an intent to check if a TTS engine is installed 
Intent checkIntent = new Intent(); 
checkIntent.setAction(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA); 
startActivityForResult(checkIntent, MY_DATA_CHECK_CODE); 

} 

public void speakClicked(View v) 
{ 
// grab the contents of the text box. 
EditText editText = (EditText) findViewById(R.id.inputText); 

mTts.speak(editText.getText().toString(),TextToSpeech.QUEUE_FLUSH, null); 
} 

public void onInit(int i) 
{ 

} 
public void onActivityResult(int requestCode, int resultCode, Intent data) 
{ 
if (requestCode == MY_DATA_CHECK_CODE) 
{ 
if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS) 
{ 
// success, create the TTS instance 
mTts = new TextToSpeech(this, this); 
} 
else 
{ 
// missing data, install it 
Intent installIntent = new Intent(); 
installIntent.setAction(
TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA); 
startActivity(installIntent); 
} 
} 
} 

@Override 
public void onDestroy() 
{ 
if (mTts != null) 
{ 
mTts.stop(); 
mTts.shutdown(); 
} 
super.onDestroy(); 
} 
} 

Answer 2

這看起來對我的文字轉語音的合成（TTS）標準的例子，可以在互聯網上隨處可見，它應該爲這樣的工作沒有任何問題。 （然而，這並不意味着沒有任何設計問題的代碼這個例子。）

也許你正在使用Android的版本太舊或者說，TTS還沒有正確設置你的電話？您是否在手機上檢查了TTS的設置？ （通常情況下，如果您的手機沒有正確設置TTS，此代碼應該打電話給正確的安裝頁面，但我記得看到一條消息，表明此部件有時可能會被炸出。）

您還應該檢查txtText在與findViewById()初始化後不爲空。