使用NSObject类中的AVAudioPlayer播放音频 [英] Play audio with AVAudioPlayer inside NSObject class

问题描述

为了整理事物，我决定创建一个名为 SoundPlayer 的类，该类将运行我的应用程序中的所有音频文件. (这样可以避免有很多重复的代码)

To organize things , I decided to create a class called SoundPlayer where will run all audio files from my app. (This would avoid having many duplicate codes)

SoundPlayer.h

SoundPlayer.h

#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
#include <AudioToolbox/AudioToolbox.h>

@interface SoundPlayer : NSObject <AVAudioPlayerDelegate>

@property (strong,nonatomic) AVAudioPlayer *backgroundMusicPlayer;

-(void)PlaySound:(NSString*)name extension:(NSString*)ext loops:(int)val;

@end

SoundPlayer.m

SoundPlayer.m

#import "SoundPlayer.h"

@implementation SoundPlayer

-(void)PlaySound:(NSString *)name extension:(NSString *)ext loops:(int)val{

    NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:name ofType:ext];
    NSURL *soundPath = [[NSURL alloc] initFileURLWithPath:soundFilePath];
    NSError *error;
    self.backgroundMusicPlayer = [[AVAudioPlayer alloc]
                                  initWithContentsOfURL:soundPath error:&error];
    self.backgroundMusicPlayer.numberOfLoops = val;
    [self.backgroundMusicPlayer prepareToPlay];
    [self.backgroundMusicPlayer play];
}

@end

此代码非常简单，并且效果很好.当用户首次打开我的应用程序时，我想播放声音，为此，我在 didFinishLaunchingWithOptions 内部调用此类，如下所示:

This code is very simple, and seems to work great. When the user open my app for first time I want to play a sound, for this I call this class inside didFinishLaunchingWithOptions, like this:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    SoundPlayer *sound = [[SoundPlayer alloc] init];
    [sound PlaySound:@"preview" extension:@"mp3" loops:0];

    return YES;//Diz que o retorno esta ok!
}

问题是声音没有被执行(现在，如果我复制了 SoundPlayer 类中的所有代码并将其放到我将要使用的类中，则声音运行得很好)是什么问题?

The problem is that the sound is not being executed (Now, if I copied all the code within the SoundPlayer class and put into the class I would use, the sound runs perfectly) what's the problem ?

推荐答案

您的SoundPlayer类超出范围并被释放，从而使声音静音.

Your SoundPlayer class is going out of scope and being deallocated, which silences the sound.

将其分配给您的应用程序委托中的成员变量:

Assign it to a member variable in your app delegate:

self.sound = [[SoundPlayer alloc] init];
[sound PlaySound:@"preview" extension:@"mp3" loops:0];

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