Question

i want to create some header file for future use but i have 1 problem

i have defined a method in lets say Rimage class called check1
now i want to call that from maiviewcont

so i did this
in mainVC.h
i defined a instance of Rimage class

#import <UIKit/UIKit.h>
@class Rimage;
@interface Rahul_imageplaceCordinatesViewController : UIViewController {

    Rimage *aRimage;
}
@property (nonatomic,copy) Rimage *aRimage;
@end

and in .m

[self.aRimage check1];
aRimage = [Rimage check1];

but both are not working

i went for both +(void)check1 and -(void)check1 in Rimage class

Answer 1

The two examples you give do very different things:

[self.aRimage check1];

invokes an check1 instance method on aRimage.

aRimage = [Rimage check1];

calls the check1 class method on the Rimage class, and assigns the result to aRimage.

In both cases, you will need to #import "Rimage.h in your .m file, else you’ll get warnings like “aRimage may not respond to ‘check1′”.

---

EDIT

Your “.h” file is declaring a property named “aRimage”, but that value will be nil until you assign something to it, by doing something like:

self.aRimage = [[[Rimage alloc] init] autorelease];

See this question for a good explanation of the difference between class methods and instance methods.

ps. and don’t forget to do a [aRimage release] in your dealloc method