ios - 意外的应用程序崩溃

Question

当我通过 xcode 构建我的应用程序时，当我按下链接到 starttimer: 的按钮时它总是崩溃。它突出显示了代码中的最后一个大括号。重要的是要注意，当我通过模拟器启动应用程序时，我可以单击按钮而不会崩溃。发生了什么？这是一些代码:

@implementation TimeController

int timeTick = 0;


NSTimer *timer;

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    labelTime.text = @"0";
}

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

- (IBAction)startTimer:(id)sender {
    [timer invalidate];
    timer= [NSTimer scheduledTimerWithTimeInterval:1.0 target:(self) selector:(@selector(tick)) userInfo:(nil) repeats:(YES)];
}

- (IBAction)resetTicktock:(id)sender {
    [timer invalidate];
    timeTick=0;
    labelTime.text = @"0";
}

-(void)tick{
    timeTick++;
    NSString *timeString = [[NSString alloc] initWithFormat:@"%d", timeTick];
    labelTime.text = timeString;
}




@end

提前致谢!

Answer 1

调用方法时不需要 ()。

代替

timer= [NSTimer scheduledTimerWithTimeInterval:1.0 target:(self) selector:(@selector(tick)) userInfo:(nil) repeats:(YES)];

你应该有

timer= [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(tick) userInfo:nil repeats:YES];