objective-c - AVplayer setNumberOfLoops 方法中无法识别的选择器

Question

像这样调用 numberOfLoops 方法时： [_player setNumberOfLoops:-1];

我收到以下错误： -[AVPlayer setNumberOfLoops:]: unrecognized selector sent to instance 0x7d52d30

如何解决这个问题？

代码：

标题：

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
@interface ViewController : UIViewController {

}


@property (strong, nonatomic) AVAudioPlayer *player;

- (IBAction)playMusic:(id)sender;


@end

执行：

#import "ViewController.h"

#import <AVFoundation/AVFoundation.h>

@interface ViewController ()

@end

@implementation ViewController

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

}

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

- (IBAction)playMusic:(id)sender {
    _player = [AVPlayer playerWithURL:[NSURL URLWithString:@"http://urlpath.wav"]];
    [_player setNumberOfLoops:-1];
    [_player prepareToPlay];
    [_player play];
}

@end

感谢您的时间，

Yoni201.

Answer 1

您创建了 的实例AVPlayer，而不是 的实例AVAudioPlayer。看起来您想要创建一个AVAudioPlayer替代（正如您为类的实际player属性选择该类所表明的那样。AVAudioPlayer实际上具有该numberOfLoops属性，而AVPlayer没有。有关更多信息，请参阅AVAudioPlayer和AVPlayer的文档。

Answer 2

AVPlayer没有numberOfLoops财产。那是`AVAudioPlayer 的一个属性。构建应用程序时不要忽略编译器警告。

此外，您定义_player为 anAVAudioPlayer但您是 alloc/init AVPlayer。

将您的代码更改为：

NSError *error = nil;
AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://urlpath.wav"] error:&error];
if (player) {
    [player setNumberOfLoops:-1];
    [player prepareToPlay];
    [player play];
    self.player = player;
} else {
    NSLog(@"Error create audio player: %@", error);
}

Answer 3

我认为您调用的方法不存在（考虑到您的错误）。

尝试：_player.numberOfLoops=-1