//申請用戶語音識別權限
 [SFSpeechRecognizer requestAuthorization:^(SFSpeechRecognizerAuthorizationStatus status) { 
 }];

typedef NS_ENUM(NSInteger, SFSpeechRecognizerAuthorizationStatus) {
 //結果未知 用戶尚未進行選擇
 SFSpeechRecognizerAuthorizationStatusNotDetermined,
 //用戶拒絕授權語音識別
 SFSpeechRecognizerAuthorizationStatusDenied,
 //設備不支持語音識別功能
 SFSpeechRecognizerAuthorizationStatusRestricted,
 //用戶授權語音識別
 SFSpeechRecognizerAuthorizationStatusAuthorized,
};

 //創(chuàng)建語音識別操作類對象
 SFSpeechRecognizer * rec = [[SFSpeechRecognizer alloc]init];
 //通過一個音頻路徑創(chuàng)建音頻識別請求
 SFSpeechRecognitionRequest * request = [[SFSpeechURLRecognitionRequest alloc]initWithURL:[[NSBundle mainBundle] URLForResource:@"7011" withExtension:@"m4a"]];
 //進行請求
 [rec recognitionTaskWithRequest:request resultHandler:^(SFSpeechRecognitionResult * _Nullable result, NSError * _Nullable error) {
  //打印語音識別的結果字符串
  NSLog(@"%@",result.bestTranscription.formattedString);
 }];

//獲取當前用戶權限狀態(tài)
+ (SFSpeechRecognizerAuthorizationStatus)authorizationStatus;
//申請語音識別用戶權限
+ (void)requestAuthorization:(void(^)(SFSpeechRecognizerAuthorizationStatus status))handler;
//獲取所支持的所有語言環(huán)境
+ (NSSet<NSLocale *> *)supportedLocales;
//初始化方法 需要注意 這個初始化方法將默認以設備當前的語言環(huán)境作為語音識別的語言環(huán)境
- (nullable instancetype)init;
//初始化方法 設置一個特定的語言環(huán)境
- (nullable instancetype)initWithLocale:(NSLocale *)locale NS_DESIGNATED_INITIALIZER;
//語音識別是否可用
@property (nonatomic, readonly, getter=isAvailable) BOOL available;
//語音識別操作類協(xié)議代理
@property (nonatomic, weak) id<SFSpeechRecognizerDelegate> delegate;
//設置語音識別的配置參數 需要注意 在每個語音識別請求中也有這樣一個屬性 這里設置將作為默認值
//如果SFSpeechRecognitionRequest對象中也進行了設置 則會覆蓋這里的值
/*
typedef NS_ENUM(NSInteger, SFSpeechRecognitionTaskHint) {
 SFSpeechRecognitionTaskHintUnspecified = 0,  // 無定義
 SFSpeechRecognitionTaskHintDictation = 1,  // 正常的聽寫風格
 SFSpeechRecognitionTaskHintSearch = 2,   // 搜索風格
 SFSpeechRecognitionTaskHintConfirmation = 3, // 短語風格
};
*/
@property (nonatomic) SFSpeechRecognitionTaskHint defaultTaskHint;
//使用回調Block的方式進行語音識別請求 請求結果會在Block中傳入
- (SFSpeechRecognitionTask *)recognitionTaskWithRequest:(SFSpeechRecognitionRequest *)request
           resultHandler:(void (^)(SFSpeechRecognitionResult * __nullable result, NSError * __nullable error))resultHandler;
//使用代理回調的方式進行語音識別請求
- (SFSpeechRecognitionTask *)recognitionTaskWithRequest:(SFSpeechRecognitionRequest *)request
            delegate:(id <SFSpeechRecognitionTaskDelegate>)delegate;
//設置請求所占用的任務隊列
@property (nonatomic, strong) NSOperationQueue *queue;

//當語音識別操作可用性發(fā)生改變時會被調用
- (void)speechRecognizer:(SFSpeechRecognizer *)speechRecognizer availabilityDidChange:(BOOL)available;

//當開始檢測音頻源中的語音時首先調用此方法
- (void)speechRecognitionDidDetectSpeech:(SFSpeechRecognitionTask *)task;
//當識別出一條可用的信息后 會調用
/*
需要注意，apple的語音識別服務會根據提供的音頻源識別出多個可能的結果 每有一條結果可用 都會調用此方法
*/
- (void)speechRecognitionTask:(SFSpeechRecognitionTask *)task didHypothesizeTranscription:(SFTranscription *)transcription;
//當識別完成所有可用的結果后調用
- (void)speechRecognitionTask:(SFSpeechRecognitionTask *)task didFinishRecognition:(SFSpeechRecognitionResult *)recognitionResult;
//當不再接受音頻輸入時調用 即開始處理語音識別任務時調用
- (void)speechRecognitionTaskFinishedReadingAudio:(SFSpeechRecognitionTask *)task;
//當語音識別任務被取消時調用
- (void)speechRecognitionTaskWasCancelled:(SFSpeechRecognitionTask *)task;
//語音識別任務完成時被調用
- (void)speechRecognitionTask:(SFSpeechRecognitionTask *)task didFinishSuccessfully:(BOOL)successfully;

//此任務的當前狀態(tài)
/*
typedef NS_ENUM(NSInteger, SFSpeechRecognitionTaskState) {
 SFSpeechRecognitionTaskStateStarting = 0,  // 任務開始
 SFSpeechRecognitionTaskStateRunning = 1,  // 任務正在運行
 SFSpeechRecognitionTaskStateFinishing = 2,  // 不在進行音頻讀入 即將返回識別結果
 SFSpeechRecognitionTaskStateCanceling = 3,  // 任務取消
 SFSpeechRecognitionTaskStateCompleted = 4,  // 所有結果返回完成
};
*/
@property (nonatomic, readonly) SFSpeechRecognitionTaskState state;
//音頻輸入是否完成
@property (nonatomic, readonly, getter=isFinishing) BOOL finishing;
//手動完成音頻輸入 不再接收音頻
- (void)finish;
//任務是否被取消
@property (nonatomic, readonly, getter=isCancelled) BOOL cancelled;
//手動取消任務
- (void)cancel;

@interface SFSpeechAudioBufferRecognitionRequest : SFSpeechRecognitionRequest

@property (nonatomic, readonly) AVAudioFormat *nativeAudioFormat;
//拼接音頻流
- (void)appendAudioPCMBuffer:(AVAudioPCMBuffer *)audioPCMBuffer;
- (void)appendAudioSampleBuffer:(CMSampleBufferRef)sampleBuffer;
//完成輸入
- (void)endAudio;

@end

//識別到的多套語音轉換信息數組 其會按照準確度進行排序
@property (nonatomic, readonly, copy) NSArray<SFTranscription *> *transcriptions;
//準確性最高的識別實例
@property (nonatomic, readonly, copy) SFTranscription *bestTranscription;
//是否已經完成 如果YES 則所有所有識別信息都已經獲取完成
@property (nonatomic, readonly, getter=isFinal) BOOL final;

//完整的語音識別準換后的文本信息字符串
@property (nonatomic, readonly, copy) NSString *formattedString;
//語音識別節(jié)點數組
@property (nonatomic, readonly, copy) NSArray<SFTranscriptionSegment *> *segments;

//當前節(jié)點識別后的文本信息
@property (nonatomic, readonly, copy) NSString *substring;
//當前節(jié)點識別后的文本信息在整體識別語句中的位置
@property (nonatomic, readonly) NSRange substringRange;
//當前節(jié)點的音頻時間戳
@property (nonatomic, readonly) NSTimeInterval timestamp;
//當前節(jié)點音頻的持續(xù)時間
@property (nonatomic, readonly) NSTimeInterval duration;
//可信度/準確度 0-1之間
@property (nonatomic, readonly) float confidence;
//關于此節(jié)點的其他可能的識別結果 
@property (nonatomic, readonly) NSArray<NSString *> *alternativeSubstrings;