Question

我使用uibuttons创建网格视图，现在需要选择并取消选择其单击按钮。一切正常，但是当我尝试按下按钮时播放声音时，app会在控制台中打印以下消息而崩溃：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIButton prepareToPlay]: unrecognized selector sent to instance 0x7526a20'

为了播放声音，我在.h文件中取了AVAudioPlayer claas的对象，并在视图中初始化它做了加载方法并按下按钮播放它，这是我的代码 .h文件

#import <UIKit/UIKit.h>
#import <AVFoundation/AVAudioPlayer.h>
#import <AudioUnit/AudioUnit.h>

@interface PlayViewController : UIViewController<AVAudioPlayerDelegate>
{
    IBOutlet UIButton *resetBtn;
    UIButton *btn[25];
    AVAudioPlayer *tapSound;

}
-(IBAction)reserBtnClkd;
@property(nonatomic,retain) AVAudioPlayer *tapSound;

@end
in .m file
- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.view setBackgroundColor:[UIColor colorWithPatternImage:[UIImage imageNamed:@"background.png"]]];
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSString *path=[[NSBundle mainBundle] pathForResource:@"button-3" ofType:@"wav"];
    AVAudioPlayer *Tapsound=[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
    self.tapSound=Tapsound;
    [Tapsound release];
    [pool release];
    [self setTheIcons];
    resetBtn.layer.cornerRadius=6.0;
    resetBtn.backgroundColor=[UIColor colorWithRed:90/255.00 green:33.00/255.00 blue:179.00/255.00 alpha:1];
    resetBtn.titleLabel.font=[UIFont fontWithName:@"Helvetica" size:22];
    [resetBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
}

#pragma mark
#pragma mark<Creating The Grid View Of Icons>
#pragma mark

-(void) setTheIcons
{
    int x=11;
    int y=55;

    for(int i=1;i<=25;i++)
    {
        btn[i]=[UIButton buttonWithType:UIButtonTypeCustom];
        btn[i].frame=CGRectMake(x, y, 58,58);
        [btn[i] addTarget:self action:@selector(btnClkd:) forControlEvents:UIControlEventTouchUpInside];
        [self.view addSubview:btn[i]];

        if(i%5==0)
        {
            x=11;
            y=y+60;
        }
        else
        {
            x=x+60;
        }
    }
    [self reserBtnClkd];
}

-(void)btnClkd:(UIButton*)sender
{
    sender.selected=!sender.selected;

    if(sender.selected)
    {
       // UIView *tempView=[[UIView alloc]initWithFrame:CGRectMake(12, 12, 34, 34)];
        UIView *tempView=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 58, 58)];
        tempView.backgroundColor=[UIColor colorWithPatternImage:[UIImage imageNamed:@"hover-effectNew.png"]];
        tempView.userInteractionEnabled=NO;
        [sender addSubview:tempView];
        [tempView release];
    }
    else
    {
        NSArray *subviewToRemove=[sender subviews];
        int i=1;
        for(UIView *view in subviewToRemove)
        {
            if(i==2)
            {
            [view removeFromSuperview];
            }
            i++;
        }
    }
    [self.tapSound prepareToPlay];
    [self.tapSound setDelegate:self];
    [self.tapSound play];

}

奇怪的是，只有当我按下按钮点击方法播放声音时App才会崩溃，否则如果我在视图中播放它确实加载然后它没有任何问题，抓我的头两天但找不到任何解决方案，请帮帮我

Answer 1

我认为问题是您的self.tapSound是UIButton（您可以在崩溃日志中看到它：'-[UIButton prepareToPlay]: unrecognized selector sent to instance 0x7526a20'。

尝试逐步调试，看看会发生什么

Answer 2

我认为因为self.tapSound引用Tapsound，所以当您调用[Tapsound release]时，它也会释放该属性。我建议直接实例化该属性，如下所示：

/*note that you have declared tapSound in your .h 
as a class variable in addition to being a property.
This means you can access it as both.
Wherever you would type self.tapSound, instead use simply tapSound
*/

tapSound = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];

应用程序崩溃播放按钮单击方法上的声音

2 个答案: