Swift应用程序崩溃与CLLocationManager上发送到实例`的“无法识别的选择器”

时间:2014-07-03 20:24:36

标签: ios swift core-location xcode6

与StackOverflow上的许多其他问题类似,运行我的应用程序时出现unrecognized selector sent to instance错误。是什么让我的情况与众不同(我认为)是用Swift写的,而且常见的原因不是这里的原因。

this问题中,解决方法是设置"自定义类"在Identity Inspector中,该视图为响应类。我检查过这种情况(注意我在某个时候重命名了这个类,但它现在肯定设置为" ViewController")。

我在下面添加了堆栈跟踪以及ViewController.swift的代码。您还可以找到所有代码here。我设法通过开始新鲜来避免这个问题,这使我能够解决我的earlier question。这个新的试用版可以在this branch中找到。但是,我想知道出了什么问题并解决了这个问题。

有些想法

我无法成功回答的一个问题是CLLocationManagerDelegate是否需要一些必要的方法?但是因为我让它在另一个分支机构工作,我怀疑它没有必要。

2014-07-03 21:50:26.056 RowingTracker2[11416:60b] -[CLLocationManager requestWhenInUseAuthorization]: unrecognized selector sent to instance 0xa10c4a0
2014-07-03 21:50:26.059 RowingTracker2[11416:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[CLLocationManager     requestWhenInUseAuthorization]: unrecognized selector sent to instance 0xa10c4a0'
*** First throw call stack:
(
    0   CoreFoundation                      0x008831e4 __exceptionPreprocess + 180
1   libobjc.A.dylib                     0x01e2a8e5 objc_exception_throw + 44
2   CoreFoundation                      0x00920243 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3   CoreFoundation                      0x0087350b ___forwarding___ + 1019
4   CoreFoundation                      0x008730ee _CF_forwarding_prep_0 + 14
5   RowingTracker2                      0x00003352 _TFC14RowingTracker214ViewController11viewDidLoadfS0_FT_T_ + 738
6   RowingTracker2                      0x000033a2 _TToFC14RowingTracker214ViewController11viewDidLoadfS0_FT_T_ + 34
7   UIKit                               0x0102f33d -[UIViewController loadViewIfRequired] + 696
8   UIKit                               0x0102f5d9 -[UIViewController view] + 35
9   UIKit                               0x00f4f267 -[UIWindow addRootViewControllerViewIfPossible] + 66
10  UIKit                               0x00f4f5ef -[UIWindow _setHidden:forced:] + 312
11  UIKit                               0x00f4f86b -[UIWindow _orderFrontWithoutMakingKey] + 49
12  UIKit                               0x00f5a3c8 -[UIWindow makeKeyAndVisible] + 65
13  UIKit                               0x00f0abc0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 2097
14  UIKit                               0x00f0f667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824
15  UIKit                               0x00f23f92 -[UIApplication handleEvent:withNewEvent:] + 3517
16  UIKit                               0x00f24555 -[UIApplication sendEvent:] + 85
17  UIKit                               0x00f11250 _UIApplicationHandleEvent + 683
18  GraphicsServices                    0x031fff02 _PurpleEventCallback + 776
19  GraphicsServices                    0x031ffa0d PurpleEventCallback + 46
20  CoreFoundation                      0x007feca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
21  CoreFoundation                      0x007fe9db __CFRunLoopDoSource1 + 523
22  CoreFoundation                      0x0082968c __CFRunLoopRun + 2156
23  CoreFoundation                      0x008289d3 CFRunLoopRunSpecific + 467
24  CoreFoundation                      0x008287eb CFRunLoopRunInMode + 123
25  UIKit                               0x00f0ed9c -[UIApplication _run] + 840
26  UIKit                               0x00f10f9b UIApplicationMain + 1225
27  RowingTracker2                      0x00008021 top_level_code + 97
28  RowingTracker2                      0x0000805b main + 43
29  libdyld.dylib                       0x024ff701 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

ViewController.swift

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
    @IBOutlet var mapview: MKMapView = nil
    var locationmgr : CLLocationManager!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        locationmgr = CLLocationManager()
        locationmgr.delegate = self
        locationmgr.requestWhenInUseAuthorization() ///< Offending line.
//        mapview.showsUserLocation = true
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

3 个答案:

答案 0 :(得分:32)

由于requestWhenInUseAuthorization方法仅适用于iOS 8(根据Apple Documentation),您必须将其打包:

Swift代码:

if (locationmgr.respondsToSelector(Selector("requestWhenInUseAuthorization"))) {
  locationmgr.requestWhenInUseAuthorization()
}

与Objective-C相同:

if ([locationmgr respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
    [locationmgr requestWhenInUseAuthorization];
}

答案 1 :(得分:19)

此代码无法在iOS 7及更低版本上运行 - 根据文档,requestWhenInUseAuthorization仅适用于iOS 8:

  

<强>状况:

     

适用于iOS 8.0及更高版本。

答案 2 :(得分:0)

以下是我用来支持iOS 7中新的核心位置方法而没有错误的内容:

SEL requestSelector = NSSelectorFromString(@"requestWhenInUseAuthorization");
if ([locationManager respondsToSelector:requestSelector]) {
   [locationManager performSelector:requestSelector withObject:NULL];
}