calling methods

hom136 · March 2011

Hi,

Noob question here, so please help :)
I really dont understand the way to call methods in objective-c. this is what i got...

so lets say we're in the header file of a class and i want to make a new view.
would i declare a method like this (not necessarily a addSubview method, just any one in general.

-(void)addSubview:(UIView *)view

and then in the implementation file i would implement that as

-(void)addSubview:(UIView *)view{
UIView* view= [[UIView alloc] initWithFrame:viewRect];
}

am i doing something wrong? something unnecessary ? please help!
thanks in advance!

baja_yu · March 2011

Add subview is a method of UIView so you don't need to declare or implement it, it's inherited. You just need to call it like


UIView *view1;
UIView *view2;

//initialize both views..

[view1 addSubview:view2];

Btw, this document is an excellent summation of the basic syntax and principles of ObjC: http://developer.apple.com/library/ios/#referencelibrary/GettingStarted/Learning_Objective-C_A_Primer/_index.html There's a great, but much longer, and thorough guide on Objective C in the documentation as well.

EDIT: Having read your "in general" part, sure, you could define a method like that (but don't name it exactly that). The problem with that approach is that you got it the wrong way round. Seeing the declaration I would expect the method called on a view would add the view passed as the parameter as the subview. Instead you are just creating a new view to the pointer being passed.

hom136 · April 2011

thank you!!

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