为什么我的TextToSpeech没有声音？

Question

I am developing an app that requires text to speech. So I read a few tts tutorials and did this:

public void buttonClick (View view) {
    TextToSpeech tts = new TextToSpeech (this, new TextToSpeech.OnInitListener () {
        @Override
        public void onInit(int status) {

        }
    });

    tts.setLanguage (Locale.UK);
    tts.speak ("Hello World", TextToSpeech.QUEUE_FLUSH, null);
}

However, when I run the app and click the button, no voice is heard, only the "click" sound of the button. This also implies that the speaker is switched on.

I guess this is because speak(String, int, HashMap<String, String>) is deprecated. This guess is proved wrong when I look at the docs:

 /** @deprecated As of API level 21, replaced by
 *         {@link #speak(CharSequence, int, Bundle, String)}.
 */

And my app's minimum SDK version is API18 and my device's android version is Android 4.3. That means speak is not deprecated. The deprecation is maybe just a bug of Android Studio.

I wonder why it makes no sound and how I can fix this problem.

Answer 1

try this example.

import android.app.Activity;
import android.hardware.SensorManager;
import android.os.Bundle;

import android.speech.tts.TextToSpeech;
import android.util.Log;

import android.view.Menu;

import android.view.View;

import android.widget.Button;


import java.util.List;
import java.util.Locale;

import android.hardware.Sensor;
import android.hardware.SensorManager;
import android.widget.Toast;

public class MainActivity extends Activity {
   TextToSpeech t1;

   Button b1;

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

      b1=(Button)findViewById(R.id.button);

      t1=new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {
         @Override
         public void onInit(int status) {
            if(status != TextToSpeech.ERROR) {
               t1.setLanguage(Locale.UK);
            }
         }
      });

      b1.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {

            t1.speak("Hi dear its working", TextToSpeech.QUEUE_FLUSH, null);
         }
      });
   }

   public void onPause(){
      if(t1 !=null){
         t1.stop();
         t1.shutdown();
      }
      super.onPause();
   }


}

and xml file is

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
   android:layout_height="match_parent" 
   tools:context=".MainActivity"
   android:transitionGroup="true">


   <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Text to Speech"
      android:id="@+id/button"
      android:layout_below="@+id/editText"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="46dp" />

</RelativeLayout>

Answer 2

public void buttonClick (View view) {
TextToSpeech tts = new TextToSpeech (this, new TextToSpeech.OnInitListener () {
    @Override
    public void onInit(int status) {
     // change required.Initialization has to finish first.   
     if(status != TextToSpeech.ERROR) {
     tts.setLanguage (Locale.UK);
     tts.speak ("Hello World", TextToSpeech.QUEUE_FLUSH, null);
     }
    }
});



}