iOS Any Difference between iOS/Mac Developing?

[benkenobi]

I've created mac apps before, and tried to create a simple app for iOS It just displays Hello world in a label after pressing a button.

For some reason it crashes with a EXC_BAD_ACCESS or SIGABRT error. Is this a xcode problem?

All I did was create a new object, with a custom class that inherits NSObject, (tried to inherit UIViewController also with no luck). The controls are connected correctly . What could I be doing wrong here?

The code and error info: (its really short)

MAObject.h:

#import <Foundation/Foundation.h>

@interface MAObject : NSObject {
  IBOutlet UILabel *displayText
}

-(IBAction)helloWorld:(id)sender;

MAObject.m:

#import "MAObject.h"
- (IBAction)helloWorld:(id)sender{
   [displayText setText:@"Hello World"];
}

Error info:

[__NSCFString helloWorld:]: unrecognized selector sent to instance 0x6842010
2012-10-18 02:54:19.686 TestApp[33418:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString helloWorld:]: unrecognized selector sent to instance 0x6842010'

 

[dejo]

You might want to take a look at this Apple tutorial: Your First iOS App.