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
demo下载地址ZQReaderDemo
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
//AVSpeechUtteranceDefaultSpeechRate
utterance.rate = _rate;
//设置音高,[0.5 - 2] 默认 = 1
//AVSpeechUtteranceMaximumSpeechRate
//AVSpeechUtteranceMinimumSpeechRate
//AVSpeechUtteranceDefaultSpeechRate
utterance.pitchMultiplier = 1;
//设置音量,[0-1] 默认 = 1
utterance.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
.h
#import
@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
.m
#import "ZQAVSpeechTool.h"
#import
@interface ZQAVSpeechTool ()
@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
//AVSpeechUtteranceDefaultSpeechRate
utterance.rate = _rate;
//设置音高,[0.5 - 2] 默认 = 1
//AVSpeechUtteranceMaximumSpeechRate
//AVSpeechUtteranceMinimumSpeechRate
//AVSpeechUtteranceDefaultSpeechRate
utterance.pitchMultiplier = 1;
//设置音量,[0-1] 默认 = 1
utterance.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。
