Question

    var searchDelayer:NSTimer?
    func searchBar(searchBar: UISearchBar!, textDidChange searchText: String!) {
        searchDelayer?.invalidate()
        searchDelayer = nil

        searchDelayer = NSTimer.scheduledTimerWithTimeInterval(1.5, target: self, selector: Selector("doDelayedSearch:"), userInfo: searchText, repeats: false)

    }

    func doDelayedSearch(text:String){
    ...
    }

为什么此代码崩溃并显示错误消息：

[__NSCFTimer copyWithZone:]: unrecognized selector sent to instance

更新：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFTimer copyWithZone:]: unrecognized selector sent to instance 0x7f9c622ae7e0'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010c05b3e5 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x000000010ba42967 objc_exception_throw + 45
    2   CoreFoundation                      0x000000010c0624fd -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x000000010bfba7ec ___forwarding___ + 988
    4   CoreFoundation                      0x000000010bfba388 _CF_forwarding_prep_0 + 120
    5   CoreFoundation                      0x000000010bf32935 CFStringCreateCopy + 229
    6   libswiftFoundation.dylib            0x000000010dc41314 _TF10Foundation24_convertNSStringToStringFCSo8NSStringSS + 116
    7   MapCode                             0x000000010a1a567e _TToFC7MapCode17MapViewController15doDelayedSearchfS0_FSST_ + 62
    8   Foundation                          0x000000010b5fce94 __NSFireTimer + 83
    9   CoreFoundation                      0x000000010bfc34d4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
    10  CoreFoundation                      0x000000010bfc3095 __CFRunLoopDoTimer + 1045
    11  CoreFoundation                      0x000000010bf863cd __CFRunLoopRun + 1901
    12  CoreFoundation                      0x000000010bf859f6 CFRunLoopRunSpecific + 470
    13  GraphicsServices                    0x000000010ecfd9f0 GSEventRunModal + 161
    14  UIKit                               0x000000010c96b990 UIApplicationMain + 1282
    15  MapCode                             0x000000010a1b3fee top_level_code + 78
    16  MapCode                             0x000000010a1b402a main + 42
    17  libdyld.dylib                       0x000000010f9d7145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

计时器回调函数必须是不带参数的函数，或者将NSTimer作为单个参数的函数。

在你的情况下，它应该是

func doDelayedSearch(timer: NSTimer) {
    let searchText = timer.userInfo as String
    // ...
}

旧答案：（以下是正确的，但不适用于此处）

计时器的目标（在您的情况下为self）需要与Objective-C兼容，即源自NSObject或标有@objc。

另见 Exposing Swift Interfaces in Objective-C ＆＃34;使用Swift与Cocoa和Objective-C＆＃34;文件（强调我的）：

@objc属性使您的Swift API在Objective-C和   Objective-C运行时。换句话说，您可以使用@objc   任何Swift方法，属性，下标，初始化器之前的属性，   或者您想要从Objective-C代码中使用的类。如果你的班级   继承自Objective-C类，编译器插入属性   对你而言   ...
  在您使用时，此属性也很有用   使用选择器实现目标操作设计模式的Objective-C类，例如NSTimer 或UIButton。

[__NSCFTimer copyWithZone：]：无法识别的选择器发送到实例

1 个答案: