Xcode：线程1：信号SIGABRT

Question

所以，我遇到了我的代码问题。 它与iOS8平稳运行，但是当我运行iOS7.1模拟器或通过iOS7.1手机运行时，出现此错误。

*** First throw call stack:   
(
0 CoreFoundation      0x004dd1e4 __exceptionPreprocess + 180 
1 libobjc.A.dylib      0x01afc8e5 objc_exception_throw + 44 
2 CoreFoundation      0x0057a243 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275 
3 CoreFoundation      0x004cd50b ___forwarding___ + 1019 
4 CoreFoundation      0x004cd0ee _CF_forwarding_prep_0 + 14 
5 testapp        0x00062e29 _TFC4hp2m14ViewController11viewDidLoadfS0_FT_T_ + 633 
6 testapp        0x00063392 _TToFC4hp2m14ViewController11viewDidLoadfS0_FT_T_ + 34 
7 UIKit        0x00d0133d -[UIViewController loadViewIfRequired] + 696 
8 UIKit        0x00d015d9 -[UIViewController view] + 35 
9 UIKit        0x00c21267 -[UIWindow addRootViewControllerViewIfPossible] + 66 
10 UIKit        0x00c215ef -[UIWindow _setHidden:forced:] + 312 
11 UIKit        0x00c2186b -[UIWindow _orderFrontWithoutMakingKey] + 49 
12 UIKit        0x00c2c3c8 -[UIWindow makeKeyAndVisible] + 65 
13 UIKit        0x00bdcbc0 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 2097 
14 UIKit        0x00be1667 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 824 
15 UIKit        0x00bf5f92 -[UIApplication handleEvent:withNewEvent:] + 3517 
16 UIKit        0x00bf6555 -[UIApplication sendEvent:] + 85 
17 UIKit        0x00be3250 _UIApplicationHandleEvent + 683 
18 GraphicsServices     0x037c2f02 _PurpleEventCallback + 776 
19 GraphicsServices     0x037c2a0d PurpleEventCallback + 46 
20 CoreFoundation      0x00458ca5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53 
21 CoreFoundation      0x004589db __CFRunLoopDoSource1 + 523 
22 CoreFoundation      0x0048368c __CFRunLoopRun + 2156 
23 CoreFoundation      0x004829d3 CFRunLoopRunSpecific + 467 
24 CoreFoundation      0x004827eb CFRunLoopRunInMode + 123 
25 UIKit        0x00be0d9c -[UIApplication _run] + 840 
26 UIKit        0x00be2f9b UIApplicationMain + 1225 
27 testapp        0x0006cd9e top_level_code + 78 
28 testapp        0x0006cddb main + 43 
29 libdyld.dylib      0x023db6d9 start + 1 
) 
libc++abi.dylib: terminating with uncaught exception of type NSException 
(lldb) 

错误发生在AppDelegate中的第一行：

@UIApplicationMain 
class AppDelegate: UIResponder, UIApplicationDelegate { 

我的应用程序进口corelocation，基础和contactlist。

Answer 1

检查您的ViewController（viewDidLoad方法）中调用的所有方法，您可能只有iOS8上可用的选择器。

要检查可用性，您可以右键单击该方法并检查文档。

以下是showViewController:sender:方法的示例。