文字閱讀例子

AVSpeechSynthesizer * synthesizer = [[AVSpeechSynthesizer alloc] init];//語(yǔ)音合成器
AVSpeechUtterance *utterance = [[AVSpeechUtterance alloc] initWithString:@"string1"];//說(shuō)話
utterance.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"en-US"];//發(fā)音
utterance.rate = 0.5f;//速率
utterance.pitchMultiplier = 0.8f;//音調(diào)
utterance.postUtteranceDelay = 0.1f;//延遲
[synthesizer speakUtterance:utterance];//添加到語(yǔ)音合成器呻纹，不會(huì)等待，程序繼續(xù)執(zhí)行 此時(shí)語(yǔ)音開(kāi)始合成

AVSpeechUtterance *utterance2 = [[AVSpeechUtterance alloc] initWithString:@"string2"];
utterance2.voice = [AVSpeechSynthesisVoice voiceWithLanguage:@"en-GB"];
utterance2.rate = 0.5f;
utterance2.pitchMultiplier = 0.8f;
utterance2.postUtteranceDelay = 0.1f;
[synthesizer speakUtterance:utterance2];//此時(shí)會(huì)等第一句結(jié)束后才會(huì)播放這句。程序不會(huì)阻塞。

發(fā)音（AVSpeechSynthesisVoice）

 @interface AVSpeechSynthesisVoice : NSObject<NSSecureCoding>
     + (NSArray<AVSpeechSynthesisVoice *> *)speechVoices;//系統(tǒng)支持的列表
     + (NSString *)currentLanguageCode;//系統(tǒng)當(dāng)前語(yǔ)言代碼
     + (nullable AVSpeechSynthesisVoice *)voiceWithLanguage:(nullable NSString *)languageCode;//通過(guò)語(yǔ)言代碼創(chuàng)建實(shí)例  使用BCP-47語(yǔ)言標(biāo)記
     + (nullable AVSpeechSynthesisVoice *)voiceWithIdentifier:(NSString *)identifier NS_AVAILABLE_IOS(9_0);//通過(guò)identifier創(chuàng)建實(shí)例
     @property(nonatomic, readonly) NSString *language;//語(yǔ)言
     @property(nonatomic, readonly) NSString *identifier NS_AVAILABLE_IOS(9_0);
     @property(nonatomic, readonly) NSString *name NS_AVAILABLE_IOS(9_0);
     @property(nonatomic, readonly) AVSpeechSynthesisVoiceQuality quality NS_AVAILABLE_IOS(9_0);

 @end

語(yǔ)句（AVSpeechUtterance）

@interface AVSpeechUtterance : NSObject<NSCopying, NSSecureCoding>//語(yǔ)句
    + (instancetype)speechUtteranceWithString:(NSString *)string;
    + (instancetype)speechUtteranceWithAttributedString:(NSAttributedString *)string API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));
    - (instancetype)initWithString:(NSString *)string;
    - (instancetype)initWithAttributedString:(NSAttributedString *)string API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));

    @property(nonatomic, retain, nullable) AVSpeechSynthesisVoice *voice;//發(fā)音
    @property(nonatomic, readonly) NSString *speechString;//閱讀的文字
    @property(nonatomic, readonly) NSAttributedString *attributedSpeechString API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));//閱讀的屬性字符串
    @property(nonatomic) float rate;             // 速率 AVSpeechUtteranceMinimumSpeechRate and AVSpeechUtteranceMaximumSpeechRate.
    @property(nonatomic) float pitchMultiplier;  // [0.5 - 2] Default = 1  音高
    @property(nonatomic) float volume;           // [0-1] Default = 1      音量

    @property(nonatomic) NSTimeInterval preUtteranceDelay;    // Default is 0.0  提前等待
    @property(nonatomic) NSTimeInterval postUtteranceDelay;   // Default is 0.0  之后等待
@end

語(yǔ)音合成器（AVSpeechSynthesizer）

 @interface AVSpeechSynthesizer : NSObject
     @property(nonatomic, weak, nullable) id<AVSpeechSynthesizerDelegate> delegate;
     @property(nonatomic, readonly, getter=isSpeaking) BOOL speaking;//狀態(tài) 是否在閱讀
     @property(nonatomic, readonly, getter=isPaused) BOOL paused;//狀態(tài)  是否暫停
     - (void)speakUtterance:(AVSpeechUtterance *)utterance; //utterance默認(rèn)進(jìn)入隊(duì)列。加入同一個(gè)在隊(duì)里的utterace會(huì)異常
     - (BOOL)stopSpeakingAtBoundary:(AVSpeechBoundary)boundary;//停止并清空閱讀隊(duì)列厌蔽。YES成功
     - (BOOL)pauseSpeakingAtBoundary:(AVSpeechBoundary)boundary;//暫停閱讀。AVSpeechBoundaryImmediate 立即停止，AVSpeechBoundaryWord 按單詞停止（把最后一個(gè)詞讀完）
     - (BOOL)continueSpeaking;//繼續(xù)
     @property(nonatomic, retain, nullable) NSArray<AVAudioSessionChannelDescription *> *outputChannels API_AVAILABLE(ios(10.0), watchos(3.0), tvos(10.0));//指定輸出頻道 用于精確調(diào)整比如外放或是耳機(jī)桥温。默認(rèn)nil系統(tǒng)處理
 @end

代理(AVSpeechSynthesizerDelegate)

 @protocol AVSpeechSynthesizerDelegate <NSObject>
     @optional
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didStartSpeechUtterance:(AVSpeechUtterance *)utterance;//已經(jīng)開(kāi)始
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didFinishSpeechUtterance:(AVSpeechUtterance *)utterance;//已經(jīng)完成
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didPauseSpeechUtterance:(AVSpeechUtterance *)utterance;//已經(jīng)停止
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didContinueSpeechUtterance:(AVSpeechUtterance *)utterance;//已經(jīng)繼續(xù)
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer didCancelSpeechUtterance:(AVSpeechUtterance *)utterance;//已經(jīng)取消
     - (void)speechSynthesizer:(AVSpeechSynthesizer *)synthesizer willSpeakRangeOfSpeechString:(NSRange)characterRange utterance:(AVSpeechUtterance *)utterance;//將要開(kāi)始讀某一段文字
 @end

總結(jié)下來(lái)能夠?qū)崿F(xiàn)，完整句子的閱讀梁丘。能夠?yàn)槊恳痪鋯为?dú)指定速度侵浸、音調(diào)、音量氛谜、音高掏觉、發(fā)音、前后等待或延遲時(shí)間值漫“母梗可以按照單詞停止或是立即停止。將要讀取某一段（無(wú)法指定大醒詈巍）或是已經(jīng)開(kāi)始或是已經(jīng)完成酱塔，或是已經(jīng)停止已經(jīng)繼續(xù)或是已經(jīng)取消都會(huì)有回調(diào)方法。無(wú)法導(dǎo)出音頻文件危虱。