ios - Xcode:无法停止从子类播放 AVAudioPlayer 音乐

Question

仍然没有解决方案 - 此处减少测试用例项目:

http://www.friendlycode.co.uk/assets/Bugfix.zip

我是 Xcode/Objective C 的新手，做了很多研究但找不到答案。这里有很多类似的问题，但没有一个能帮助我解决这个问题。

文件:

app.h
app.m
Settings.h
Settings.m

我有一些背景音乐播放，当应用程序通过 ViewController.m 文件中的 ViewDidLoad 启动时开始播放。

如果触摸音乐开关并将其设置为关闭，我将尝试从 Settings.m 文件中停止此操作。

请看下面的代码(删除了不必要的 socket /方法等)

NSLog 输出'attempting to stop audio' 但音频没有停止。我想我已经正确引用了 ViewController 类，所以不确定为什么它不会停止？

应用.h

#import <UIKit/UIKit.h>
#import <Social/Social.h>
#import "AVFoundation/AVAudioPlayer.h"

@interface ViewController : GAITrackedViewController <AVAudioPlayerDelegate, UIActionSheetDelegate>
{
    // removed
}

@property (nonatomic, retain) AVAudioPlayer *BackgroundMusicPlayer;

@end

应用.m

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Play Background music
    [self PlayBackgroundMusic];
}

-(void)PlayBackgroundMusic
{
    NSString* resourcePath = [[NSBundle mainBundle]
                            pathForResource:@"music-file"
                            ofType:@"aiff"];

    NSLog(@"Path to play: %@", resourcePath);
    NSError* err;

    //Initialize our player pointing to the path to our resource
    _BackgroundMusicPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:
              [NSURL fileURLWithPath:resourcePath] error:&err];

    if( err ){
        //bail!
        NSLog(@"Failed with reason: %@", [err localizedDescription]);
    }
    else{
        //set our delegate and begin playback
        _BackgroundMusicPlayer.delegate = self;
        [_BackgroundMusicPlayer play];
        _BackgroundMusicPlayer.numberOfLoops = -1;
        _BackgroundMusicPlayer.currentTime = 0;
        _BackgroundMusicPlayer.volume = 0.5;
    }
}

设置.h

#import <UIKit/UIKit.h>
#import "app.h"

@interface Settings : GAITrackedViewController <AVAudioPlayerDelegate, UIActionSheetDelegate>
{
    IBOutlet UIButton *BackButton;
    IBOutlet UISwitch *MusicSwitch;
    IBOutlet UISwitch *SoundFXSwitch;


    // Get instance of ViewController object
    ViewController *home;
}

-(IBAction)BackButton:(id)sender;
-(IBAction)ToggleMusic:(id)sender;
-(IBAction)ToggleSoundFX:(id)sender;


@end

设置.m

#import "Settings.h"

@interface Settings ()

@end

@implementation Settings

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

}

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

-(IBAction)ToggleMusic:(id)sender {

    // Get instance of ViewController object

    //home = [[ViewController alloc] init];

    if (MusicSwitch.on)
    {
        [home.BackgroundMusicPlayer play];
    }
    else {
       [home.BackgroundMusicPlayer stop];
        NSLog(@"Attempting to stop audio");

    }
}

-(IBAction)ToggleSoundFX:(id)sender {

    if (SoundFXSwitch.on)
    {
    }
    else{

    }
}

-(IBAction)BackButton:(id)sender
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

我认为问题出在 ViewController *home 上。

您的 AvAudioPlayer 对象位于 ViewController 界面的 app.h 中。

但是在您的代码中，您没有初始化 ViewController 对象“home”在settings.m中。如此有效地，您正在尝试访问并阻止一个玩家未创建。

要访问 AVAudioPlayer 对象，请在 settings.h 的 viewDidload 中添加以下代码。

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //initialise the audioPlayer object.
    home=[[ViewController alloc] init];
}