在AVFoundation框架中AVAudioRecorder類專門處理錄音操作，支持多種音頻格式。下面是常用的屬性和方法：

 

屬性 說明 @property(readonly, getter=isRecording) BOOL recording; 是否正在錄音，只讀 @property(readonly) NSURL *url 錄音文件地址，只讀 @property(readonly) NSDictionary *settings 錄音文件設置，只讀 @property(readonly) NSTimeInterval currentTime 錄音時長，只讀，注意僅僅在錄音狀態可用 @property(readonly) NSTimeInterval deviceCurrentTime 輸入設置的時間長度，只讀，注意此屬性一直可訪問 @property(getter=isMeteringEnabled) BOOL meteringEnabled; 是否啟用錄音測量，如果啟用錄音測量可以獲得錄音分貝等數據信息 @property(nonatomic, copy) NSArray *channelAssignments 當前錄音的通道 對象方法 說明 - (instancetype)initWithURL:(NSURL *)url settings:(NSDictionary *)settings error:(NSError **)outError 錄音機對象初始化方法，注意其中的url必須是本地文件url，settings是錄音格式、編碼等設置 - (BOOL)prepareToRecord 准備錄音，主要用於創建緩沖區，如果不手動調用，在調用record錄音時也會自動調用 - (BOOL)record 開始錄音 - (BOOL)recordAtTime:(NSTimeInterval)time 在指定的時間開始錄音，一般用於錄音暫停再恢復錄音 - (BOOL)recordForDuration:(NSTimeInterval) duration 按指定的時長開始錄音 - (BOOL)recordAtTime:(NSTimeInterval)time forDuration:(NSTimeInterval) duration 在指定的時間開始錄音，並指定錄音時長 - (void)pause; 暫停錄音 - (void)stop; 停止錄音 - (BOOL)deleteRecording; 刪除錄音，注意要刪除錄音此時錄音機必須處於停止狀態 - (void)updateMeters; 更新測量數據，注意只有meteringEnabled為YES此方法才可用 - (float)peakPowerForChannel:(NSUInteger)channelNumber; 指定通道的測量峰值，注意只有調用完updateMeters才有值 - (float)averagePowerForChannel:(NSUInteger)channelNumber 指定通道的測量平均值，注意只有調用完updateMeters才有值 代理方法 說明 - (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag 完成錄音 - (void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder *)recorder error:(NSError *)error 錄音編碼發生錯誤

 

 

AVAudioRecorder創建錄音機時除了指定路徑外還必須指定錄音設置信息，因為錄音機必須知道錄音文件的格式、采樣率、通道數、每個采樣點的位數等信息，通常只需要幾個常用設置。關於錄音設置詳見幫助文檔中的“AV Foundation Audio Settings Constants”。

以下代碼實現錄音，暫停，繼續，取消，停止，播放功能。

 

#import ViewController.h

#import 

#define kAudioFileName @test.caf

@interface ViewController ()

@property (nonatomic,strong) AVAudioRecorder *audioRecorder; //音頻錄音機
@property (nonatomic,strong) AVAudioPlayer *audioPlayer;     //音頻播放器
@property (nonatomic,strong) NSTimer *timer;            //錄音監控

@property (weak, nonatomic) IBOutlet UIProgressView *audioPower;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setAudioSession];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/**
 *  設置音頻會話
 */
-(void)setAudioSession{
    AVAudioSession *audioSession=[AVAudioSession sharedInstance];
    //設置為播放和錄音狀態，以便可以在錄制完之後播放錄音
    [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
    [audioSession setActive:YES error:nil];
}

/**
 *  錄音文件設置
 *
 *  @return 返回錄音設置
 */
- (NSDictionary *)getAudioSetting
{
    NSMutableDictionary *dic = [NSMutableDictionary dictionary];
    [dic setObject:@(kAudioFormatLinearPCM) forKey:AVFormatIDKey];  //設置錄音格式
    [dic setObject:@(8000) forKey:AVSampleRateKey];                 //設置采樣率
    [dic setObject:@(1) forKey:AVNumberOfChannelsKey];              //設置通道，這裡采用單聲道
    [dic setObject:@(8) forKey:AVLinearPCMBitDepthKey];             //每個采樣點位數，分為8，16，24，32
    [dic setObject:@(YES) forKey:AVLinearPCMIsFloatKey];            //是否使用浮點數采樣
    return dic;
}

/**
 *  錄音存儲路徑
 *
 *  @return 返回存儲路徑
 */
- (NSURL *)getSavePath
{
    NSString *url = [NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask,YES) lastObject];
    url = [url stringByAppendingPathComponent:kAudioFileName];
    return [NSURL URLWithString:url];
}


- (NSTimer *)timer
{
    if (!_timer) {
        _timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(audioPowerChange) userInfo:nil repeats:YES];
    }
    return _timer;
}

- (AVAudioRecorder *)audioRecorder
{
    if (!_audioRecorder) {
        NSError *error = nil;
        _audioRecorder = [[AVAudioRecorder alloc] initWithURL:[self getSavePath] settings:[self getAudioSetting] error:&error];
        _audioRecorder.delegate = self;
        _audioRecorder.meteringEnabled = YES; //是否啟用錄音測量，如果啟用錄音測量可以獲得錄音分貝等數據信息
        if (error) {
            NSLog(@創建錄音機對象發生錯誤:%@,error.localizedDescription);
            return nil;
        }
    }
    return _audioRecorder;
}

- (AVAudioPlayer *)audioPlayer
{
    if (!_audioPlayer) {
        NSError *error = nil;
        _audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[self getSavePath] error:&error];
        if (error) {
            NSLog(@創建音頻播放器對象發生錯誤:%@,error.localizedDescription);
            return nil;
        }
    }
    return _audioPlayer;
}

#pragma mark - 
#pragma mark - AVAudioRecorderDelegate
//錄音成功
- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag
{
    if (![self.audioPlayer isPlaying]) {
        [self.audioPlayer play];
    }
}
//錄音失敗
- (void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder *)recorder error:(NSError *)error
{
    
}

#pragma mark - 
#pragma mark - Action

- (void)audioPowerChange{
    [self.audioRecorder updateMeters];  //更新測量值
    float power = [self.audioRecorder averagePowerForChannel:1]; //取得第一個通道的音頻，注意音頻強度范圍時-160到0
    self.audioPower.progress = (1.0/160)*(power+160);
}

/**
 *  點擊錄音按鈕
 *
 *  @param sender 錄音按鈕
 */
- (IBAction)startRecord:(id)sender {
    
    if (![self.audioRecorder isRecording]) {
        [self.audioRecorder record];
        self.timer.fireDate = [NSDate distantPast];
    }
}

/**
 *  點擊取消錄音按鈕
 *
 *  @param sender 取消錄音按鈕
 */
- (IBAction)cancelRecord:(id)sender {
    self.audioRecorder.delegate = nil;
    if ([self.audioRecorder isRecording]) {
       [self.audioRecorder stop];
    }
    self.audioRecorder = nil;
}

/**
 *  點擊暫定按鈕
 *
 *  @param sender 暫停按鈕
 */
- (IBAction)pause:(id)sender {
    if ([self.audioRecorder isRecording]) {
        [self.audioRecorder pause];
        self.timer.fireDate = [NSDate distantFuture];
    }
}

/**
 *  點擊恢復按鈕
 *  恢復錄音只需要再次調用record，AVAudioSession會幫助你記錄上次錄音位置並追加錄音
 *
 *  @param sender 恢復按鈕
 */
- (IBAction)goon:(id)sender {
    [self startRecord:nil];
}

/**
 *  點擊停止按鈕
 *
 *  @param sender 停止按鈕
 */
- (IBAction)stop:(id)sender {
    if ([self.audioRecorder isRecording]) {
        [self.audioRecorder stop];
        self.timer = [NSDate distantFuture];
    }
}

/**
 *  點擊播放按鈕
 *
 *  @param sender 播放按鈕
 */
- (IBAction)play:(id)sender {
    
    if (![self.audioPlayer isPlaying]) {
        [self.audioPlayer play];
    }
}