ios application crashes when “lock screen”

Question

I have a problem with tab bar application. Everything working good, but if i send in simulator command "lock screen" debugger console says that application crashed. What can it be?

debugger message:

GNU gdb 6.3.50-20050815 (Apple version gdb-1518) (Sat Feb 12 02:52:12 UTC 2011)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin".Attaching to process 407.
2011-03-16 23:35:59.084 Smokie[407:207] -[OverviewController applicationWillResignActive:]: unrecognized selector sent to instance 0x4e20650
2011-03-16 23:35:59.088 Smokie[407:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[OverviewController applicationWillResignActive:]: unrecognized selector sent to instance 0x4e20650'
*** Call stack at first throw:
(
•   0   CoreFoundation                      0x00dcb5a9 __exceptionPreprocess + 185
•   1   libobjc.A.dylib                     0x00f1f313 objc_exception_throw + 44
•   2   CoreFoundation                      0x00dcd0bb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
•   3   CoreFoundation                      0x00d3c966 ___forwarding___ + 966
•   4   CoreFoundation                      0x00d3c522 _CF_forwarding_prep_0 + 50
•   5   Foundation                          0x00025669 _nsnote_callback + 145
•   6   CoreFoundation                      0x00da39f9 __CFXNotificationPost_old + 745
•   7   CoreFoundation                      0x00d2293a _CFXNotificationPostNotification + 186
•   8   Foundation                          0x0001b20e -[NSNotificationCenter postNotificationName:object:userInfo:] + 134
•   9   UIKit                               0x002bc0a8 -[UIApplication _setActivated:] + 334
•   10  UIKit                               0x002bf905 -[UIApplication _handleApplicationSuspend:eventInfo:] + 292
•   11  UIKit                               0x002c9039 -[UIApplication handleEvent:withNewEvent:] + 4127
•   12  UIKit                               0x002c0abf -[UIApplication sendEvent:] + 71
•   13  UIKit                               0x002c5f2e _UIApplicationHandleEvent + 7576
•   14  GraphicsServices                    0x01723992 PurpleEventCallback + 1550
•   15  CoreFoundation                      0x00dac944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
•   16  CoreFoundation                      0x00d0ccf7 __CFRunLoopDoSource1 + 215
•   17  CoreFoundation                      0x00d09f83 __CFRunLoopRun + 979
•   18  CoreFoundation                      0x00d09840 CFRunLoopRunSpecific + 208
•   19  CoreFoundation                      0x00d09761 CFRunLoopRunInMode + 97
•   20  GraphicsServices                    0x017221c4 GSEventRunModal + 217
•   21  GraphicsServices                    0x01722289 GSEventRun + 115
•   22  UIKit                               0x002c9c93 UIApplicationMain + 1160
•   23  Smokie                              0x00001c30 main + 102
•   24  Smokie                              0x00001bc1 start + 53
)
terminate called after throwing an instance of 'NSException'
sharedlibrary apply-load-rules all
Current language:  auto; currently objective-c
(gdb) 

Answer 1

For some reason, unclear from the question, an instance of OverviewController is in place where an UIApplicationDelegate should be. May be a mixup with outlets in the MainWindow xib? In the Main Windo xib, the "delegate" outlet in the UIApplication instance should be assigned to the UIApplicationDelegate. Is that the case?

I say this because the error is caused by the method applicationWillResignActive: being called on the OverviewController and not found. applicationWillResignActive: is the method the application calls in the application delegate before locking.