AudioServices歸屬AudioToolbox框架，AudioToolbox是更底層的音頻框架。

• 每個音頻文件都有唯一的SystemSoundID

typedef UInt32      SystemSoundID;

• 震動，iPod無法震動

CF_ENUM(SystemSoundID)
{
    kSystemSoundID_Vibrate              = 0x00000FFF
};

• 創建SystemSoundID

extern OSStatus 
AudioServicesCreateSystemSoundID(   CFURLRef                    inFileURL,
                                    SystemSoundID*              outSystemSoundID)
                                                                __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_2_0);

NSString  *path = [[NSBundle mainBundle] pathForResource:@"videoChat_calling" ofType:@"mp3"];
NSURL *url = [NSURL fileURLWithPath: path];
SystemSoundID outSystemSoundID = 0;
AudioServicesCreateSystemSoundID((__bridge CFURLRef)(url), &outSystemSoundID);

注意：文件類型填寫錯誤會crash。

• 注銷SystemSoundID

extern OSStatus 
AudioServicesDisposeSystemSoundID(SystemSoundID inSystemSoundID)                                    
                                                                __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_2_0);

• 播放帶震動的音頻

extern void 
AudioServicesPlayAlertSound(SystemSoundID inSystemSoundID)                                          
                                                                __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_2_0);
extern void
AudioServicesPlayAlertSoundWithCompletion(  SystemSoundID inSystemSoundID,
                                            void (^__nullable inCompletionBlock)(void))
                                                                    __OSX_AVAILABLE_STARTING(__MAC_10_11, __IPHONE_9_0);

• 播放音頻

extern void 
AudioServicesPlaySystemSound(SystemSoundID inSystemSoundID)                                         
                                                                __OSX_AVAILABLE_STARTING(__MAC_10_5,__IPHONE_2_0);
extern void
AudioServicesPlaySystemSoundWithCompletion(     SystemSoundID inSystemSoundID,
                                                void (^__nullable inCompletionBlock)(void))
                                                                        __OSX_AVAILABLE_STARTING(__MAC_10_11, __IPHONE_9_0);

• 錯誤類型

CF_ENUM(OSStatus)
{
    kAudioServicesNoError                                   =  0,
    kAudioServicesUnsupportedPropertyError                  = 'pty?',
    kAudioServicesBadPropertySizeError                      = '!siz',
    kAudioServicesBadSpecifierSizeError                     = '!spc',

    kAudioServicesSystemSoundUnspecifiedError               = -1500,
    kAudioServicesSystemSoundClientTimedOutError            = -1501,
    kAudioServicesSystemSoundExceededMaximumDurationError   = -1502
};

提升代碼質量最神圣的三部曲：模塊設計(謀定而后動) -->無錯編碼(知止而有得) -->開發自測(防患于未然)