在没有按钮的情况下，无法使用文本或JSon文件在活动开始时让安卓text to speech阅读

import android.speech.tts.TextToSpeech;
import android.speech.tts.TextToSpeech.OnInitListener;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import java.util.Locale;

public class MainActivity extends AppCompatActivity implements OnInitListener {
    private TextToSpeech textToSpeech;

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

        // 初始化TextToSpeech对象
        textToSpeech = new TextToSpeech(this, this);
    }

    @Override
    public void onInit(int status) {
        if (status == TextToSpeech.SUCCESS) {
            // 设置语言为英文
            int result = textToSpeech.setLanguage(Locale.ENGLISH);

            if (result == TextToSpeech.LANG_MISSING_DATA || result == TextToSpeech.LANG_NOT_SUPPORTED) {
                // 语言数据丢失或不支持，无法进行语音转换
                // 可以在这里进行错误处理或使用其他语言
            } else {
                // 文本转语音
                textToSpeech.speak("Hello, welcome to the activity!", TextToSpeech.QUEUE_FLUSH, null);
            }
        } else {
            // TextToSpeech初始化失败，无法进行语音转换
            // 可以在这里进行错误处理
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        // 释放TextToSpeech对象
        if (textToSpeech != null) {
            textToSpeech.stop();
            textToSpeech.shutdown();
        }
    }
}

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />