Android Studio中的TextToSpeech没有被调用/不起作用

Question

以下创建意图并调用另一个视图组的简单代码均来自基本的第一个应用程序教程。

https://developer.android.com/training/basics/firstapp/starting-activity.html

我使用这个问题作为获取 TTS 的指南，应用程序运行 toast 和视图，但跳过文本到语音： Text to speech(TTS)-Android

然后我尝试添加 TTS 通话/课程。我对 Android 很陌生，所以想知道是否有人可以向我解释，或者指出我如何使用这些类并围绕它们构建以帮助我的一般理解的正确方向，但总的来说，这个问题的解决方案会很棒，非常感谢！

包 com.example.ollie.myapplication3;

    import android.content.Context;
    import android.content.Intent;
    import android.net.Uri;
    import android.os.Build;
    import android.speech.tts.TextToSpeech;
    import android.support.annotation.RequiresApi;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.EditText;
    import android.widget.Toast;

    import com.google.android.gms.appindexing.Action;
    import com.google.android.gms.appindexing.AppIndex;
    import com.google.android.gms.appindexing.Thing;
    import com.google.android.gms.common.api.GoogleApiClient;

    import java.util.Locale;

    public class MainActivity extends AppCompatActivity implements TextToSpeech.OnInitListener {

        public static final String EXTRA_MESSAGE = "com.example.myapplication.MESSAGE";
        /**
         * ATTENTION: This was auto-generated to implement the App Indexing API.
         * See https://g.co/AppIndexing/AndroidStudio for more information.
         */
        private GoogleApiClient client;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            // ATTENTION: This was auto-generated to implement the App Indexing API.
            // See https://g.co/AppIndexing/AndroidStudio for more information.
            client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
        }

        /**
         * Called when user clicks send button
         */
        public void sendMessage(View view) {

            TextToSpeech tts = new TextToSpeech(this, this);
            tts.setLanguage(Locale.US);
            tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null);

            Context context = getApplicationContext();
            CharSequence text = "Hello toast!";
            int duration = Toast.LENGTH_LONG;

            Toast toast = Toast.makeText(context, text, duration);
            toast.show();

            Intent intent = new Intent(this, DisplayMessageActivity.class);
            EditText editText = (EditText) findViewById(R.id.edit_message);
            String message = editText.getText().toString();
            intent.putExtra(EXTRA_MESSAGE, message);
            startActivity(intent);
        }

        @Override
        public void onInit(int status) {
            TextToSpeech tts = new TextToSpeech(this, this);
            tts.setLanguage(Locale.US);
            tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null);
        }
    }

Answer 1

尝试使您的“tts”变量成为本地变量（在活动中），以确保您使用的是您已实例化的同一实例，而不是每次按下按钮时都创建一个新实例。

像这样：

public class MainActivity extends AppCompatActivity {

private TextToSpeech tts;


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

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

}


public void sendMessage(View view) {
    tts.speak("Text to say aloud", TextToSpeech.QUEUE_ADD, null, null);

    ...
}

}