CODEWITHSUNDEEP
objective-c
emil.c
emil.c

Reputation: 2018

How to access object that I'm addressing from a method

I guess this is a very basic question, but anyway I don't know how to call this approach therefore I cannot find it anywhere online.

Let's say I have an object myImg:

UIImageView *myImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"myImg.png"]];

And a method:

-(void)myMethod {
  // access myImg and change something on it
}

How can I access myImg object within myMethod when I fire it:

[myImg myMethod];

Is it even possible or do I have to create a custom class for UIImageView with my custom method?

Upvotes: 0

Views: 46

Answers (3)

virindh
virindh

Reputation: 3765

change the method to:

-(void)myMethod:(UIImageView *myImg) {
   // access myImg and change something on it
 }

UPDATE: You are looking for how to implement a category. See the following link, provided by apple https://developer.apple.com/library/ios/documentation/cocoa/conceptual/ProgrammingWithObjectiveC/CustomizingExistingClasses/CustomizingExistingClasses.html

Upvotes: -1

Mick MacCallum
Mick MacCallum

Reputation: 130193

If you've declared myMethod in a category of UIImageView then you can reference myImg by using self.

@interface UIImageView (Category)

- (void)myMethod;

@end

@implementation UIImageView (Category)

- (void)myMethod
{
//    reference self here for reference to myImg
}

@end

Upvotes: 3

Gavin
Gavin

Reputation: 8200

Add a property to the class that you're declaring the method in:

@property (nonatomic, strong) UIImageView *myImg;

Then change your line where you create the UIImageView:

self.myImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"myImg.png"]];

Then from your method, you can access the UIImageView by referencing self.myImg.

Upvotes: -1

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