App crashes on button Click Action iOS - ios

Question

I have created a button and added its action at runtime. The entire view is created at runtime.
Calling the action saveUserProfileSetting on click crashes the app "NSInvalidArgument: Unrecornized selector sent to a instance . It was working okay when the code was present in
another class. I tried to create an new class for it and it crashes.
#interface LASplashViewer : NSObject
+(void) showSplashScreen;
+(void) dismissSplashScreen;
#end
(void) showSplashScreen
{
UIView *mainScreen = [[[UIApplication sharedApplication]delegate]window];
UIView *windowBlocker = [[UIView alloc]initWithFrame:mainScreen.frame];
windowBlocker.tag = 999;
windowBlocker.backgroundColor = [UIColor clearColor];
UIButton *saveButton = [[UIButton alloc]initWithFrame:CGRectMake(200, 430, 420, 30)];
[saveButton setTitle:#"Save" forState:UIControlStateNormal];
[saveButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[saveButton addTarget:self action:#selector(saveUserProfileSetting) forControlEvents:UIControlEventTouchUpInside];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(165, 200, 450, 480)];
imageView.layer.cornerRadius=10;
imageView.layer.masksToBounds = YES;
[windowBlocker addSubview:imageView];
[imageView addSubview:saveButton];
imageView.userInteractionEnabled = true;
[mainScreen addSubview:windowBlocker];
}
-(void) saveUserProfileSetting
{
// TODO: if validation is successful save the below data. and dismiss the splash screen.
NSUserDefaults *userSettings = [[NSUserDefaults alloc] init];
[userSettings setObject:fullName.text forKey:#"name_pref"];
NSLog(#"%#fullname" , fullName);
[userSettings setObject:jobTitle.text forKey:#"title_pref"];
[userSettings setObject:streetName.text forKey:#"street_name_pref"];
[userSettings setObject:suburbs.text forKey:#"suburb_pref"];
[userSettings setObject:postCode.text forKey:#"postcode_pref"];
[userSettings setObject:phoneNum.text forKey:#"phone_no_pref"];
[userSettings setObject:fax.text forKey:#"fax_pref"];
[userSettings setObject:mobileNumber.text forKey:#"mobile_no_pref"];
[userSettings setObject:email.text forKey:#"email_pref"];
[userSettings synchronize];
}
Call to the method is Show is in another
class - // HomeViewController.
(void)viewDidLoad
{
[super viewDidLoad];
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"isFirstLaunch"])
{
// app already launched
[[NSUserDefaults standardUserDefaults]synchronize];
}
else
{
[[NSUserDefaults standardUserDefaults]setBool:YES forKey:#"isFirstLaunch"];
[[NSUserDefaults standardUserDefaults]synchronize];
// call this method only for the first load.
//[self performSelector:#selector() withObject:nil afterDelay:0.5];
[self performSelector:#selector(saveProfile) withObject:Nil afterDelay:0.5];
}
}
-(void) saveProfile
{
[LASplashViewer showSplashScreen];
}
log :
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[LASplashViewer saveUserProfileSetting]: unrecognized selector sent to class 0x2a4dc'
please guide me. Thanks

Answer 1

[LASplashViewer saveUserProfileSetting] is crashing because it is not a static function. Make your function as
1) + (void)saveUserProfileSetting { }
2) Or call as
LASplashViewer *viewer = [[LASplashViewer alloc] init];
[viewer saveUserProfileSetting];

Answer 2

Looks like you call instance selector from class method
LASplashViewer have class method showSplashScreen where you call instance method saveUserProfileSetting
to solve problem try make saveUserProfileSetting also class method (replace - to +)

Answer 3

+(void) showSplashScreen; is a class method, from which you are setting action for the button
[saveButton addTarget:self action:#selector(saveUserProfileSetting) forControlEvents:UIControlEventTouchUpInside];
Here the target is self. Inside a class method self refers to its own Class not to the instance. So here the target of the method is LASplashViewer not its instance. Your button expects a class method like +(void)saveUserProfileSetting. It is not finding a class method with such name. So its crashing. I hope you understood root cause.
Solution is make method as a class method
+ (void)saveUserProfileSetting