OC高效率52之用前綴避免命名空間衝突

#import <Foundation/Foundation.h>
/// Apple宣稱其保留使用全部「兩字母前綴」的權利，本身選用的前綴應該是三個字母
@class EocSoundPlayer;
@protocol EOCSoundPlayerDelegate <NSObject>
//播放完畢回調
-(void) soundPlayerDidFinish:(EocSoundPlayer *)player;

@end

@interface EocSoundPlayer : NSObject

@property (nonatomic , weak) id <EOCSoundPlayerDelegate> delegate;

-(id) initWithURL:(NSURL *)url;
-(void) playSound;
@end

#import "EocSoundPlayer.h"
#import  <AudioToolbox/AudioToolbox.h>
void completion (SystemSoundID ssID,void *clientData)
{
    EocSoundPlayer *player = (__bridge EocSoundPlayer *)clientData;
    
    if ([player.delegate respondsToSelector:@selector(soundPlayerDidFinish:)])
    {
        [player.delegate soundPlayerDidFinish:player];
    }
}
@implementation EocSoundPlayer
{
    SystemSoundID _systemSoundID;
}

-(id)initWithURL:(NSURL *)url
{
    if ((self = [super init]))
    {
        AudioServicesCreateSystemSoundID((__bridge CFURLRef)url, &_systemSoundID);
    }
    return self;
}

-(void) dealloc
{
    AudioServicesDisposeSystemSoundID(_systemSoundID);
}

-(void)playSound
{
    AudioServicesAddSystemSoundCompletion(_systemSoundID, NULL, NULL,completion,(__bridge void *)self), AudioServicesPlaySystemSound(_systemSoundID);

}
@end