Question

我正在尝试在用户触摸圆角矩形按钮三秒后进行警报显示但是当我运行应用程序时它不起作用（但Xcode说“没有问题”）。

这是我的.h文件：

@interface ViewController : UIViewController {
}

-(IBAction)timerAlert:(id)sender;
-(void)showAlert;

这是我的实施文件：

@implementation ViewController

-(IBAction)timerAlert:(id)sender {

    [NSTimer scheduledTimerWithTimeInterval:3 target:sender selector:@selector(showAlert) userInfo:nil repeats:NO];
}

-(void)showAlert {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Three seconds have elapsed" message:@"Please return to the app" delegate:self cancelButtonTitle:@"Return" otherButtonTitles:nil, nil];
    [alert show];
}

这是我收到的错误消息：

2012-04-04 19:25:42.833 DisplayAfterTime[740:f803]
-[UIRoundedRectButton showAlert]: unrecognized selector sent to instance 0x6b74220 
2012-04-04 19:25:42.837 DisplayAfterTime[740:f803]
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIRoundedRectButton showAlert]: unrecognized selector sent to instance 0x6b74220'
*** First throw call stack: (0x13c7022 0x1558cd6 0x13c8cbd 0x132ded0 0x132dcb2 0x94deb6 0x139b936 0x139b3d7 0x12fe790 0x12fdd84 0x12fdc9b 0x12b07d8 0x12b088a 0x11626 0x1edd 0x1e45) terminate called throwing an exception

所以我做错了什么？

Answer 1

您正在设置定时器以发送到错误的目标。它应该是自我。

几秒钟后显示警报视图

1 个答案: