xcode unrecognized selector sent to instance error - xcode

Question

I am new to xcode iOS programming and I really need your help with the error of unrecognised selector sent to instance. Below is my implementation
//.h file
#interface AppAccountController : UIViewController <UIAlertViewDelegate>{
IBOutlet UITextField *txtName;
IBOutlet UITextField *txtEmail;
IBOutlet UIDatePicker *dateOB;
IBOutlet UITextField *txtPwd;
IBOutlet UITextField *txtRePwd;
}
- (IBAction)btnSave:(id)sender;
#end
//.m file
#interface AppAccountController ()
#property (strong, nonatomic) IBOutlet UITextField *txtName;
#property (strong, nonatomic) IBOutlet UITextField *txtEmail;
#property (strong, nonatomic) IBOutlet UIDatePicker *dateOB;
#property (strong, nonatomic) IBOutlet UITextField *txtPwd;
#property (strong, nonatomic) IBOutlet UITextField *txtRePwd;
#property (strong, nonatomic) IBOutlet UIButton *btnSave;
#end
#implementation AppAccountController
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (IBAction)btnSave:(id)sender {
// Create strings to store the text info
NSString *name = [txtName text];
NSString *email = [txtEmail text];
NSDate *dob = [dateOB date];
NSString *passwd = [txtPwd text];
NSString *repasswd = [txtRePwd text];
if ([txtName.text isEqualToString:#""])
{
[txtName becomeFirstResponder];
UIAlertView* finalCheck = [[UIAlertView alloc]
initWithTitle:#"Attention"
message:#"Name Field is empty. Please enter a name"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] ;
[finalCheck show];
finalCheck.tag = 1;
}
else if ([txtEmail.text isEqualToString:#""])
{
[txtEmail becomeFirstResponder];
UIAlertView* finalCheck = [[UIAlertView alloc]
initWithTitle:#"Attention"
message:#"Email Field is empty. Please enter an Email"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] ;
[finalCheck show];
finalCheck.tag = 2;
}
else if ([txtPwd.text isEqualToString:#""])
{
[txtPwd becomeFirstResponder];
UIAlertView* finalCheck = [[UIAlertView alloc]
initWithTitle:#"Attention"
message:#"Password Field is empty. Please enter a Password"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] ;
[finalCheck show];
finalCheck.tag = 3;
}
else if ([txtRePwd.text isEqualToString:#""])
{
[txtRePwd becomeFirstResponder];
UIAlertView* finalCheck = [[UIAlertView alloc]
initWithTitle:#"Attention"
message:#"Confirm Password Field is empty. Please enter to confirm Password"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] ;
[finalCheck show];
finalCheck.tag = 4;
}
else if (![passwd isEqualToString:repasswd])
{
[txtPwd becomeFirstResponder];
UIAlertView* finalCheck = [[UIAlertView alloc]
initWithTitle:#"Attention"
message:#"Passwords do not match. Please enter to confirm Password"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil] ;
[finalCheck show];
finalCheck.tag = 5;
}
else{
// Store the data
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:name forKey:#"name"];
[defaults setObject:email forKey:#"email"];
[defaults setObject:passwd forKey:#"passwd"];
[defaults setObject:dob forKey:#"dob"];
[defaults synchronize];
NSLog(#"Data saved");
[self performSegueWithIdentifier:#"saveLoad" sender:self];
}
}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
if(alertView.tag == 1) {
[txtName becomeFirstResponder];
NSLog(#"Name AlertView is clicked");
}
else if(alertView.tag == 2) {
[txtEmail becomeFirstResponder];
NSLog(#"Email AlertView is clicked");
}
else if(alertView.tag == 3) {
[txtPwd becomeFirstResponder];
NSLog(#"Password AlertView is clicked");
}
else if(alertView.tag == 4) {
[txtRePwd becomeFirstResponder];
NSLog(#"Re-Password AlertView is clicked");
}
else if(alertView.tag == 5) {
[txtRePwd becomeFirstResponder];
NSLog(#"Re-Password AlertView is clicked");
}
}
#end
Whenever I press the btnSave button or after moving on to another UI element (one element gaining focus after another one losses it), I get unrecognised selector sent to instance.
UPDATE
2014-12-18 18:06:23.794 XPB[964:35743] -[AppAccountController btnSave:forEvent:]: unrecognized selector sent to instance 0x7fd949d923f0
2014-12-18 18:06:23.834 XPB[964:35743] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AppAccountController btnSave:forEvent:]: unrecognized selector sent to instance 0x7fd949d923f0'
*** First throw call stack:
(
0 CoreFoundation 0x000000010bd2df35 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010a182bb7 objc_exception_throw + 45
2 CoreFoundation 0x000000010bd3504d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x000000010bc8d27c ___forwarding___ + 988
4 CoreFoundation 0x000000010bc8ce18 _CF_forwarding_prep_0 + 120
5 UIKit 0x00000001087e98be -[UIApplication sendAction:to:from:forEvent:] + 75
6 UIKit 0x00000001088f0410 -[UIControl _sendActionsForEvents:withEvent:] + 467
7 UIKit 0x00000001088ef7df -[UIControl touchesEnded:withEvent:] + 522
8 UIKit 0x000000010882f308 -[UIWindow _sendTouchesForEvent:] + 735
9 UIKit 0x000000010882fc33 -[UIWindow sendEvent:] + 683
10 UIKit 0x00000001087fc9b1 -[UIApplication sendEvent:] + 246
11 UIKit 0x0000000108809a7d _UIApplicationHandleEventFromQueueEvent + 17370
12 UIKit 0x00000001087e5103 _UIApplicationHandleEventQueue + 1961
13 CoreFoundation 0x000000010bc63551 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
14 CoreFoundation 0x000000010bc5941d __CFRunLoopDoSources0 + 269
15 CoreFoundation 0x000000010bc58a54 __CFRunLoopRun + 868
16 CoreFoundation 0x000000010bc58486 CFRunLoopRunSpecific + 470
17 GraphicsServices 0x000000010c64e9f0 GSEventRunModal + 161
18 UIKit 0x00000001087e8420 UIApplicationMain + 1282
19 XPB 0x00000001083965b3 main + 115
20 libdyld.dylib 0x000000010ce4b145 start + 1
21 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

The problem is that btnSave: and btnSave:forEvent: are two different things.
Your AppAccountController has a btnSave: method, so it can be sent the btnSave: message. But it has no btnSave:forEvent: method. Unfortunately, that's the selector you specified to be used whenever the button is pressed. The button is trying to send btnSave:forEvent: to your AppAccountController, and AppAccountController doesn't know what to do with that. So it crashes.
The easiest solution is to fix the button so that it sends btnSave: and not btnSave:forEvent:. (You will almost never need the two-parameter variant of an action method in any case.)