Question

我搜索了问题，但找不到类似的案例。

我使用本教程播放testSound.mp3 - 在iPad模拟器上按下按钮时的文件： http://mobileorchard.com/easy-audio-playback-with-avaudioplayer/

如果playSound-Method在我的ViewController.m中，但是在我的Sound.m（具有相同的方法）中，它就是这样（它播放声音）。代码被执行（NSLog说：“Sound.m playSound执行”），但根本没有声音。

我真的很感激这里的一些帮助，猜猜我完全陷入了困境...... :(

祝你好运， - 茶壶

// ViewController.h

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#import "Sound.h"

@interface ViewController : UIViewController {

    AVAudioPlayer *audioPlayer;

}

- (IBAction)pressButton:(id)sender;
- (void)playSound: (NSString*) soundFile volume : (NSInteger) volume repeats : (NSInteger) repeats;

@end

// ViewController.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading thea view, typically from a nib.

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)pressButton:(id)sender {

    NSLog (@"Method: pressButton");

    [self playSound: @"testSound.mp3" volume: 2 repeats: 2 url : url]; //It works!

    Sound *tempSound = [[Sound alloc] init];
    [tempSound playSound: @"testSound.mp3" volume: 2 repeats: 2]; // Doesn't work. -> Says "Sound.m playSound executed", but there is no Sound.

}

- (void)playSound: (NSString*) soundFile volume : (NSInteger) volume repeats : (NSInteger) repeats {

    NSLog(@"ViewControler playSound");

    NSError *error;
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
    audioPlayer.numberOfLoops = -1;

    if (audioPlayer == nil){
        NSLog([error description]);
        NSLog(@"ViewController.m playSound NOT executed");
    }
    else{
        [audioPlayer play];
        NSLog(@"ViewController.m playSound executed");
    } 

}

@end

// Sound.h

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

@interface Sound : NSObject {
    AVAudioPlayer *audioPlayer;
}

- (void) playSound: (NSString*) soundFile volume : (NSInteger) volume repeats : (NSInteger) repeats;

@end

// Sound.m

#import "Sound.h"

@implementation Sound

- (void)playSound: (NSString*) soundFile volume : (NSInteger) volume repeats : (NSInteger) repeats {

    NSLog(@"Sound playSound");

    NSError *error;
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
    audioPlayer.numberOfLoops = -1;

    if (audioPlayer == nil){
        NSLog([error description]);
        NSLog(@"Sound.m playSound NOT executed");
    }
    else{
        [audioPlayer play];
        NSLog(@"Sound.m playSound executed");
    } 

}

@end

Answer 1

您的代码中存在一些不一致：playSound:具有NSString参数，但该方法中的AVAudioPlayer使用NSURL。然后设置numberOfLoops = -1（表示无限重复）而不是numberOfLoops = repeat。

但主要问题就是这里（假设您使用“自动引用计数”进行编译）

Sound *tempSound = [[Sound alloc] init];
[tempSound playSound: @"testSound.mp3" volume: 2 repeats: 2];

tempSound对象在<{1}}离开时 deallocated ，因为不再存在对该对象的强引用。

如果将实例变量（或属性）pressButton:添加到视图控制器类，并将其分配给

sound

然后它应该按预期工作。

或者， 您可以通过在对象内维护“自引用”来防止sound = [[Sound alloc] init]; [sound playSound: @"testSound.mp3" volume: 2 repeats: 2];对象过早释放，只有在声音播放完毕：

Sound

当然，你不应该以“无限重复”来做到这一点！

相同的功能，都被执行，没有声音合二为一

1 个答案: