java - Android Studio 中的 TextToSpeech 未被调用/无法工作

Question

下面的简单代码生成 Intent 并调用另一个 View 组，全部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 View ，但跳过文本到语音: Text to speech(TTS)-Android

然后我尝试添加 TTS 通话/类(class)。我对 Android 很陌生，所以想知道是否有人可以向我解释，或者为我指明如何使用这些类并围绕它们进行构建的正确方向，以帮助我进行一般理解，但总的来说，解决这个问题会很棒，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

尝试将“tts”变量设置为本地变量(在 Activity 中)，以便确保使用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);

    ...
}

}