Application crash on UIButton click : iphone - objective-c

Question

I have a View base iphone application
I add a NSObject class AddNewContact and take its object in IB
AddNewContact.h
#import <Foundation/Foundation.h>
#interface AddNewContact : NSObject {
}
-(IBAction)abc:(id)sender;
#end
AddNewContact.m
#import "AddNewContact.h"
#implementation AddNewContact
-(IBAction)abc:(id)sender{
NSLog(#"this is test");
}
#end
I bind a UIButton action to abc: on clicking the button application crashes, even NSLog is also not logged
but if I bind the button action to other classes function then it working ok
Crash Log
2011-06-08 15:40:30.368 myApp[5466:207] -[NSCFString abc:]: unrecognized selector sent to instance 0x6b7b1c0
2011-06-08 15:40:30.416 myApp[5466:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString abc:]: unrecognized selector sent to instance 0x6b7b1c0'
*** Call stack at first throw:
(
0 CoreFoundation 0x02ad9b99 __exceptionPreprocess + 185
1 libobjc.A.dylib 0x02c2940e objc_exception_throw + 47
2 CoreFoundation 0x02adb6ab -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
3 CoreFoundation 0x02a4b2b6 ___forwarding___ + 966
4 CoreFoundation 0x02a4ae72 _CF_forwarding_prep_0 + 50
5 UIKit 0x0039e7f8 -[UIApplication sendAction:to:from:forEvent:] + 119
6 UIKit 0x00429de0 -[UIControl sendAction:to:forEvent:] + 67
7 UIKit 0x0042c262 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 527
8 UIKit 0x0042ae0f -[UIControl touchesEnded:withEvent:] + 458
9 UIKit 0x003c23d0 -[UIWindow _sendTouchesForEvent:] + 567
10 UIKit 0x003a3cb4 -[UIApplication sendEvent:] + 447
11 UIKit 0x003a89bf _UIApplicationHandleEvent + 7672
12 GraphicsServices 0x0306a822 PurpleEventCallback + 1550
13 CoreFoundation 0x02abaff4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
14 CoreFoundation 0x02a1b807 __CFRunLoopDoSource1 + 215
15 CoreFoundation 0x02a18a93 __CFRunLoopRun + 979
16 CoreFoundation 0x02a18350 CFRunLoopRunSpecific + 208
17 CoreFoundation 0x02a18271 CFRunLoopRunInMode + 97
18 GraphicsServices 0x0306900c GSEventRunModal + 217
19 GraphicsServices 0x030690d1 GSEventRun + 115
20 UIKit 0x003acaf2 UIApplicationMain + 1160
21 myApp 0x00001fa4 main + 102
22 myApp 0x00001f35 start + 53
)
terminate called after throwing an instance of 'NSException'
Can anybody tell me where I am wrong
Thanks
Amit Battan

Answer 1

You will be releasing your AddNewContact view controller, the view is still in the superview but the viewController is released, the button tries to call 'abc' on AddNewContact controller which no longer exists...