ios电子书语音阅读

非常感谢大家利用自己宝贵的时间来阅读我的文章 , 上一篇文章写了Epub的加密一个实现方式，《ios Epub加密及解密阅读的一种实现方式》，今天这篇文章主要说一下电子书的语音阅读，这个功能也基本上是阅读器的标配了。希望这篇文章能给你的开发过程带来一些帮助。喜欢的可以关注一下我的简书、我的博客

先看下效果图，声音没法展示，下载ZQReaderDemo运行看效果吧

关于电子书阅读这这块就不说了，还是在XDSReader的基础上修改，添加了语音阅读的功能

在网上查了些资料，IOS7.0之后系统添加了文字转语音的API，AVFoundation框架下的AVSpeechSynthesizer类，具体使用代码如下，也可参考ZQReaderDemo中的ZQAVSpeechTool

//初始化语音合成器_avSpeaker = [[AVSpeechSynthesizer alloc] init];_avSpeaker.delegate = self;//初始化要说出的内容AVSpeechUtterance *utterance = [[AVSpeechUtterance alloc] initWithString:_paragraphs[_currentParagraphs]];//设置语速,语速介于AVSpeechUtteranceMaximumSpeechRate和AVSpeechUtteranceMinimumSpeechRate之间//AVSpeechUtteranceMaximumSpeechRate//AVSpeechUtteranceMinimumSpeechRate//AVSpeechUtteranceDefaultSpeechRateutterance.rate = _rate;//设置音高,[0.5 - 2] 默认 = 1//AVSpeechUtteranceMaximumSpeechRate//AVSpeechUtteranceMinimumSpeechRate//AVSpeechUtteranceDefaultSpeechRateutterance.pitchMultiplier = 1;//设置音量,[0-1] 默认 = 1utterance.volume = 1;//读一段前的停顿时间utterance.preUtteranceDelay = 0.5;//读完一段后的停顿时间utterance.postUtteranceDelay = 0;//设置声音,是AVSpeechSynthesisVoice对象//AVSpeechSynthesisVoice定义了一系列的声音, 主要是不同的语言和地区.//voiceWithLanguage: 根据制定的语言, 获得一个声音.//speechVoices: 获得当前设备支持的声音//currentLanguageCode: 获得当前声音的语言字符串, 比如”ZH-cn”//language: 获得当前的语言//通过特定的语言获得声音AVSpeechSynthesisVoice *voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"zh-CN"];//通过voicce标示获得声音//AVSpeechSynthesisVoice *voice = [AVSpeechSynthesisVoice voiceWithIdentifier:AVSpeechSynthesisVoiceIdentifierAlex];utterance.voice = voice;//开始朗读[_avSpeaker speakUtterance:utterance];

既然语音转文字实现方法找到了，那么剩下的都是逻辑上的问题了，最后整理了一下实现思路，用户在阅读菜单上点击语音按钮，开始语音阅读当前页内容，首先取出当前页的所有文本，当前页读完跳转下一页继续阅读，后考虑到高亮问题，又把每一页的文本拆分成段落进行阅读，当读完一段开始读下一段，当前页读完就继续读下一页，当前章读完就读下一章，整体思路想好了就开整。

1、创建了一个单例工具类ZQAVSpeechTool，代码如下

#import <Foundation/Foundation.h>@interface ZQAVSpeechTool : NSObject+(instancetype)shareSpeechTool;//开始朗读
- (void)speechTextWith:(NSString *)text;
//暂停朗读
- (void)pauseSpeech;
//继续朗读
- (void)continueSpeech;
//结束朗读
- (void)StopSpeech;
//切换语速
- (void)changeRate:(CGFloat)rate;@end

#import "ZQAVSpeechTool.h"
#import <AVFoundation/AVFoundation.h>@interface ZQAVSpeechTool ()<AVSpeechSynthesizerDelegate>@property (nonatomic ,strong)AVSpeechSynthesizer *avSpeaker;@property (nonatomic ,strong)NSArray *paragraphs;@property (nonatomic ,assign)NSInteger currentParagraphs;@property (nonatomic ,assign)CGFloat rate;@end@implementation ZQAVSpeechTool// 单例
+(instancetype)shareSpeechTool {static ZQAVSpeechTool *instance;static dispatch_once_t onceToken;dispatch_once(&onceToken, ^{instance = [[ZQAVSpeechTool alloc]init];});return instance;
}- (void)speechTextWith:(NSString *)text
{if (!(text.length>0)) {return;}if (_avSpeaker) {//把每一页文字拆分成段_paragraphs =[text componentsSeparatedByString:@"\n"];_currentParagraphs = 0;[self speechParagraphWith:_paragraphs[_currentParagraphs]];}else{//初次阅读NSUserDefaults *useDef = [NSUserDefaults standardUserDefaults];_rate = [useDef floatForKey:@"speechRate"];if (!_rate) {_rate = 0.5;}_paragraphs =[text componentsSeparatedByString:@"\n"];_currentParagraphs = 0;[[NSNotificationCenter defaultCenter] postNotificationName:@"speechParagraph" object:_paragraphs[_currentParagraphs]];//初始化语音合成器_avSpeaker = [[AVSpeechSynthesizer alloc] init];_avSpeaker.delegate = self;//初始化要说出的内容AVSpeechUtterance *utterance = [[AVSpeechUtterance alloc] initWithString:_paragraphs[_currentParagraphs]];//设置语速,语速介于AVSpeechUtteranceMaximumSpeechRate和AVSpeechUtteranceMinimumSpeechRate之间//AVSpeechUtteranceMaximumSpeechRate//AVSpeechUtteranceMinimumSpeechRate//AVSpeechUtteranceDefaultSpeechRateutterance.rate = _rate;//设置音高,[0.5 - 2] 默认 = 1//AVSpeechUtteranceMaximumSpeechRate//AVSpeechUtteranceMinimumSpeechRate//AVSpeechUtteranceDefaultSpeechRateutterance.pitchMultiplier = 1;//设置音量,[0-1] 默认 = 1utterance.volume = 1;//读一段前的停顿时间utterance.preUtteranceDelay = 0.5;//读完一段后的停顿时间utterance.postUtteranceDelay = 0;//设置声音,是AVSpeechSynthesisVoice对象//AVSpeechSynthesisVoice定义了一系列的声音, 主要是不同的语言和地区.//voiceWithLanguage: 根据制定的语言, 获得一个声音.//speechVoices: 获得当前设备支持的声音//currentLanguageCode: 获得当前声音的语言字符串, 比如”ZH-cn”//language: 获得当前的语言//通过特定的语言获得声音AVSpeechSynthesisVoice *voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"zh-CN"];//通过voicce标示获得声音//AVSpeechSynthesisVoice *voice = [AVSpeechSynthesisVoice voiceWithIdentifier:AVSpeechSynthesisVoiceIdentifierAlex];utterance.voice = voice;//开始朗读[_avSpeaker speakUtterance:utterance];}}- (void)speechParagraphWith:(NSString *)Paragraph
{[[NSNotificationCenter defaultCenter] postNotificationName:@"speechParagraph" object:Paragraph];AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:Paragraph];utterance.rate = _rate;[_avSpeaker speakUtterance:utterance];
}
//切换语速
- (void)changeRate:(CGFloat)rate
{_rate = rate;//[_avSpeaker stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];    //初始化语音合成器
//    _avSpeaker = [[AVSpeechSynthesizer alloc] init];
//    _avSpeaker.delegate = self;AVSpeechUtterance *utterance = [AVSpeechUtterance speechUtteranceWithString:_paragraphs[_currentParagraphs]];utterance.rate = rate;utterance.pitchMultiplier = 1;utterance.volume = 1;utterance.preUtteranceDelay = 0.5;utterance.postUtteranceDelay = 0;[_avSpeaker speakUtterance:utterance];NSUserDefaults *useDef = [NSUserDefaults standardUserDefaults];[useDef setFloat:rate forKey:@"speechRate"];[useDef synchronize];}- (void)pauseSpeech
{//暂停朗读//AVSpeechBoundaryImmediate 立即停止//AVSpeechBoundaryWord    当前词结束后停止[_avSpeaker pauseSpeakingAtBoundary:AVSpeechBoundaryImmediate];
}- (void)continueSpeech
{[_avSpeaker continueSpeaking];}- (void)StopSpeech
{//AVSpeechBoundaryImmediate 立即停止//AVSpeechBoundaryWord    当前词结束后停止[_avSpeaker stopSpeakingAtBoundary:AVSpeechBoundaryImmediate];_avSpeaker = nil;[XDSReadManager sharedManager].speeching = NO;[[NSNotificationCenter defaultCenter] postNotificationName:@"speechDidStop" object:nil];}#pragma mark -
#pragma mark - AVSpeechSynthesizerDelegate
//已经开始
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didStartSpeechUtterance:(AVSpeechUtterance *)utterance{}
//已经说完
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utterance{_currentParagraphs+=1;if (_currentParagraphs<_paragraphs.count) {//读下一段[self speechParagraphWith:_paragraphs[_currentParagraphs]];}else{NSInteger currentPage = CURRENT_RECORD.currentPage;NSInteger currentChapter = CURRENT_RECORD.currentChapter;if (currentPage < CURRENT_RECORD.totalPage - 1) {//下一页currentPage += 1;}else{if (currentChapter < CURRENT_RECORD.totalChapters - 1) {//下一章currentChapter += 1;currentPage = 0;}else{//全书读完[self StopSpeech];return;}}[[XDSReadManager sharedManager] readViewJumpToChapter:currentChapter page:currentPage];NSString *content = CURRENT_RECORD.chapterModel.pageStrings[currentPage];[self speechTextWith:content];}}//已经暂停
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didPauseSpeechUtterance:(AVSpeechUtterance *)utterance{}
//已经继续说话
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didContinueSpeechUtterance:(AVSpeechUtterance *)utterance{}
//已经取消说话
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didCancelSpeechUtterance:(AVSpeechUtterance *)utterance{}
//将要说某段话
- (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer willSpeakRangeOfSpeechString:(NSRange)characterRange utterance:(AVSpeechUtterance *)utterance{//    DebugLog(@"%@",utterance.speechString);}@end

2、为XDSReadManager添加开始语音阅读的方法，并添加一个用于判断当前阅读状态的属性

- (void)begainSpeech;@property (nonatomic ,assign)BOOL speeching;

方法的实现

//开始语音阅读
- (void)begainSpeech
{//取出当前页文字内容XDSChapterModel *currentChapterModel = _bookModel.record.chapterModel;NSInteger currentPage = _bookModel.record.currentPage;NSString *content = currentChapterModel.pageStrings[currentPage];//开始朗读本页文字[[ZQAVSpeechTool shareSpeechTool] speechTextWith:content];self.speeching = YES;}

3、在弹出菜单时判断是否正在朗读，是则弹出语音阅读菜单ZQSpeechMenuView,因为AVSpeechSynthesizer只有女声，所以菜单只是加了调节语速和暂停/播放、退出的功能，没有添加切换男女声的功能

主要功能实现

//暂停/播放
- (void)pauseBtnClick:(UIButton *)sender
{if (_pauseBtn.selected) {[[ZQAVSpeechTool shareSpeechTool] continueSpeech];}else{[[ZQAVSpeechTool shareSpeechTool] pauseSpeech];}_pauseBtn.selected = !_pauseBtn.selected;
}//退出
- (void)stopBtnClick
{_pauseBtn.selected = NO;[[ZQAVSpeechTool shareSpeechTool] StopSpeech];[self removeFromSuperview];
}//切换语速
- (void)sliderValueChanged:(UISlider *)slider{[[ZQAVSpeechTool shareSpeechTool] changeRate:slider.value];_pauseBtn.selected = NO;
}

4、高亮正在阅读段落

- (void)highlightTextWith:(NSString *)text{//移除上一段背景色if (_currentRange.length>0) {[_readAttributedContent removeAttribute:NSBackgroundColorAttributeName range:_currentRange];}//设置当前朗读段落背景色NSRange range = [_content rangeOfString:text];_currentRange = range;[_readAttributedContent addAttribute:NSBackgroundColorAttributeName value:RGB(150, 220, 240) range:range];self.readAttributedContent = _readAttributedContent;[self reloadView];
}

大工搞成，具体的实现逻辑及代码见ZQReaderDemo，语音菜单界面约束使用的SDAutoLayout，可以根据自己习惯进行更改。