iOS 播放音效

音效:通俗的说是短音频,音频文件必须满足下面的条件

　　1、播放的时间不能超过30秒

　　2、数据必须是 PCM或者IMA4流格式

　　3、必须被打包成下面三个格式之一：Core Audio Format (.caf), Waveform audio (.wav), 或者 Audio Interchange File (.aiff)

1.引入框架

1 #import <AudioToolbox/AudioToolbox.h>

2.播放音效

 1 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
 2 {
 3     // 声明SoundID
 4     SystemSoundID soundID ;
 5     self.soundID = soundID;
 6     // 获取音效文件的url
 7     NSURL *url = [[NSBundle mainBundle] URLForResource:@"m_10.wav" withExtension:nil];
 8     // 根据url创建
 9     AudioServicesCreateSystemSoundID((__bridge CFURLRef)url, &soundID);
10     AudioServicesPlaySystemSound(soundID);
11 };

　　记忆技巧:

　　1.播放音效的核心代码,申明音效ID,然后播放音效

　　 1 SystemSoundID soundID ; 2 AudioServicesPlaySystemSound(soundID);

　　2.用下面这句给soundID赋值

　　 1 AudioServicesCreateSystemSoundID((__bridge CFURLRef)url, &soundID);

　　3.赋值语句有2个参数,一个是音效文件资源路径,另外一个就是之前申明soundID了

　　 1 NSURL *url = [[NSBundle mainBundle] URLForResource:@"m_10.wav" withExtension:nil];

3.播放完音效后,应该销毁

1 - (void)didReceiveMemoryWarning
2 {
3     [super didReceiveMemoryWarning];
4     AudioServicesDisposeSystemSoundID(self.soundID);
5     self.soundID = 0;
6 }

重构上述代码,提供一个播放音效的工具类,重构代码来自MJ老师

1.工具类的.h文件

 1 #import <Foundation/Foundation.h>
 2 
 3 @interface MJAudioTool : NSObject
 4 
 5 /**
 6  *  播放音效
 7  *
 8  *  @param filename 音效文件名
 9  */
10 + (void)playSound:(NSString *)filename;
11 
12 /**
13  *  销毁音效
14  *
15  *  @param filename 音效文件名
16  */
17 + (void)disposeSound:(NSString *)filename;
18 @end

2.工具类.m文件

 1 #import "MJAudioTool.h"
 2 #import <AudioToolbox/AudioToolbox.h>
 3 
 4 @implementation MJAudioTool
 5 
 6 // 字典: filename作为key, soundID作为value
 7 // 存放所有的音频ID
 8 static NSMutableDictionary *_soundIDDict;
 9 + (void)initialize
10 {
11     _soundIDDict = [NSMutableDictionary dictionary];
12 }
13 
14 + (void)playSound:(NSString *)filename
15 {
16     if (!filename) return;
17     
18     // 1.从字典中取出soundID
19     SystemSoundID soundID = [_soundIDDict[filename] unsignedLongValue];
20     if (!soundID) { // 创建
21         // 加载音效文件
22         NSURL *url = [[NSBundle mainBundle] URLForResource:filename withExtension:nil];
23         
24         if (!url) return;
25         
26         // 创建音效ID
27         AudioServicesCreateSystemSoundID((__bridge CFURLRef)url, &soundID);
28         
29         // 放入字典
30         _soundIDDict[filename] = @(soundID);
31     }
32     
33     // 2.播放
34     AudioServicesPlaySystemSound(soundID);
35 }
36 
37 + (void)disposeSound:(NSString *)filename
38 {
39     if (!filename) return;
40     
41     SystemSoundID soundID = [_soundIDDict[filename] unsignedLongValue];
42     if (soundID) {
43         // 销毁音效ID
44         AudioServicesDisposeSystemSoundID(soundID);
45         
46         // 从字典中移除
47         [_soundIDDict removeObjectForKey:filename];
48     }
49 }
50 
51 @end

3.控制器的.m文件

播放音效

1 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
2 {
3     [MJAudioTool playSound:@"buyao.wav"];
4     [MJAudioTool playSound:@"m_03.wav"];
5 }

销毁音效

1 - (void)didReceiveMemoryWarning
2 {
3     [super didReceiveMemoryWarning];
4     
5     [MJAudioTool disposeSound:@"m_03.wav"];
6     [MJAudioTool disposeSound:@"buyao.wav"];
7 }