如何正确使NSTimer无效

Question

我有一个带有NSTimer的iPhone应用程序,名为pressTimer,每次有人触摸此按钮时都会消失.问题是他们触摸了很多按钮,我希望计时器在他们抬起手指时停止.所以我在我的.h中声明了pressTimer并在.m中合成它然后分配并在我创建的TouchDown动作上启动它.我在TouchUpInside操作上使用代码[pressTimer invalidate],该操作应该取消定时器,因为它是一个全局变量.这似乎取消计时器罚款,但后来当我去到实际跳闸定时器,程序完全冻结起来,虽然我没有得到任何的代码错误或警告.我是菜鸟,所以请不要太粗暴:0

更新:控制台日志 - 谢谢大家!

continue
2010-07-01 16:39:30.981 Clickkr[1573:307] -[__NSCFData invalidate]: unrecognized selector sent to instance 0x154b40
2010-07-01 16:39:30.999 Clickkr[1573:307] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFData invalidate]: unrecognized selector sent to instance 0x154b40'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x309a5fd3 __exceptionPreprocess + 114
    1   libobjc.A.dylib                     0x318b58a5 objc_exception_throw + 24
    2   CoreFoundation                      0x309a9a77 -[NSObject(NSObject) doesNotRecognizeSelector:] + 102
    3   CoreFoundation                      0x309a8f15 ___forwarding___ + 508
    4   CoreFoundation                      0x3093b680 _CF_forwarding_prep_0 + 48
    5   Clickkr                             0x00002b23 -[MyViewController addOne:] + 42
    6   CoreFoundation                      0x309307ad -[NSObject(NSObject) performSelector:withObject:withObject:] + 24
    7   UIKit                               0x31e1f829 -[UIApplication sendAction:to:from:forEvent:] + 84
    8   UIKit                               0x31e1f7c9 -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 32
    9   UIKit                               0x31e1f79b -[UIControl sendAction:to:forEvent:] + 38
    10  UIKit                               0x31e1f4ed -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 356
    11  UIKit                               0x31e1fb3b -[UIControl touchesEnded:withEvent:] + 342
    12  UIKit                               0x31e1e4ed -[UIWindow _sendTouchesForEvent:] + 368
    13  UIKit                               0x31e1de67 -[UIWindow sendEvent:] + 262
    14  UIKit                               0x31e19b5b -[UIApplication sendEvent:] + 298
    15  UIKit                               0x31e19507 _UIApplicationHandleEvent + 5022
    16  GraphicsServices                    0x30a8c147 PurpleEventCallback + 666
    17  CoreFoundation                      0x3097baab __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 26
    18  CoreFoundation                      0x3097d84f __CFRunLoopDoSource1 + 166
    19  CoreFoundation                      0x3097e62d __CFRunLoopRun + 520
    20  CoreFoundation                      0x309278eb CFRunLoopRunSpecific + 230
    21  CoreFoundation                      0x309277f3 CFRunLoopRunInMode + 58
    22  GraphicsServices                    0x30a8b6ef GSEventRunModal + 114
    23  GraphicsServices                    0x30a8b79b GSEventRun + 62
    24  UIKit                               0x31dc32a7 -[UIApplication _run] + 402
    25  UIKit                               0x31dc1e17 UIApplicationMain + 670
    26  Clickkr                             0x00002333 main + 70
    27  Clickkr                             0x000022e8 start + 40
)
terminate called after throwing an instance of 'NSException'
Program received signal:  “SIGABRT”.

Answer 1

这是我使计时器无效的方式:

[timer invalidate];
timer = nil;

您可能遇到的问题是,一旦您的计时器失效,它将从运行时循环中删除,当有人想要访问它时,您的程序崩溃.使其无效后,只需将其设为零即可.这样,如果有人想发送消息或对其做任何事情,它会将其发送给零.