Flutter中 TTS（播放文本功能）的使用

请支持原文：http://tryenough.com/flutter-tts

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需求

在flutter中指定一段文字，播放语音。

实现

1.添加库引用

我们这里使用Dart的 tts库，首先在配置文件中添加这个库的引用：

在pubspec.yaml文件中添加如下代码引用：

dependencies:
  tts: ^1.0.2

执行命令，获取该库：

flutter packages get

请支持原文：http://tryenough.com/flutter-tts

使用时引入头文件：

import 'package:tts/tts.dart';

2.创建tts_helper类，作为使用tts的帮助类

import 'package:tts/tts.dart';

import 'dart:async';
import 'dart:io';

/// Singleton tool class for tts

/// Use TtsHelper step:
///
/// Method : #isLanguageAvailable judge language, here language is _languageMap's values like "en-US",instead of the type of 'en' etc..
///
/// Method : #getTtsLanguage  help you convert "en" to "en-US".
///
/// Method : #setLanguage help you set Language , but "en-US" is default value
///
/// use example:
/// TtsHelper.instance.speak("speech content");
/// or
/// TtsHelper.instance.setLanguageAndSpeak("speech content", "en-US");
/// ...
class TtsHelper {

  // Locale to tss language map
  static final Map<String, String> _languageMap = {
    'en': "en-US",
    'zh': "zh-CN",
    "ar": "ar-SA",
    "cs": "cs-CZ",
    "da": "da-DK",
    "de": "de-DE",
    "el": "el-GR",
    "es": "es-ES",
    "fi": "fi-FI",