是C语言的低层次API，可以播放短的声音，不能暂停或停止等控制。

可以用来制作游戏音效和操作音，以及提醒用户要做某件事，还可以发出振动提醒，但是只能在iphone设备上。

播放系统声音

主要用于游戏音效和操作声音等。

#import "ViewController.h"
#import <AudioToolbox/AudioToolbox.h>

@interface ViewController ()

- (IBAction)playSystemSound:(id)sender;

@end

#pragma mark -定义一个回调函数，用于当声音播放完成之后回调
void SoundFinishedPlayingCallback(SystemSoundID sound_id, void * user_data)
{
    //注销声音播放完成事件回调函数
    AudioServicesRemoveSystemSoundCompletion(sound_id);
    //释放SystemSoundID
    AudioServicesDisposeSystemSoundID(sound_id);
}

@implementation ViewController

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

- (IBAction)playSystemSound:(id)sender
{
    NSString *path = [[NSBundle mainBundle] pathForResource:@"AlertChordStroke" ofType:@"wav"];
    NSURL *system_sound_url = [NSURL fileURLWithPath:path];
    
    SystemSoundID system_sound_id;
    //创建SystemSoundID
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)system_sound_url, &system_sound_id);
    //注销声音播放完成事件回调函数
    AudioServicesAddSystemSoundCompletion(system_sound_id, NULL, NULL, SoundFinishedPlayingCallback, NULL);
    //播放系统声音
    AudioServicesPlaySystemSound(system_sound_id);
}

@end

发出警告提醒

只在iphone下有振动。

- (IBAction)alertSound:(id)sender
{
    NSURL *system_sound_url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"AlertChordStroke" ofType:@"wav"]];
    SystemSoundID system_sound_id;
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)system_sound_url, &system_sound_id);
    AudioServicesAddSystemSoundCompletion(system_sound_id, NULL, NULL, SoundFinishedPlayingCallback, NULL);
    AudioServicesPlayAlertSound(system_sound_id);
}

振动

- (IBAction)vibrate:(id)sender
{
    NSString *deviceModel = [[UIDevice currentDevice] model];
    if ([deviceModel isEqualToString:@"iPhone"])
    {
        AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
    }
    else
    {
        UIAlertController *alertC = [[UIAlertController alloc] init];
        [alertC setTitle:@"提示"];
        UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"设备不支持" style:UIAlertActionStyleDefault handler:nil];
        [alertC addAction:alertAction];
        [self presentViewController:alertC animated:YES completion:nil];
    }
}