Question

I have instance of interface that displays a map.
I am calling to that map from other interface and displaying it, now i want to start a function (func5) that in the map interface.

I’m creating:

myMap *map = (myMap*) [[UIApplication sharedApplication] delegate];
[map func5:2];

this func5 i declared in myMap interface.

-(void) func5:(int) num;

but i’m getting an error when trying to run this line: [map func5:2];

'NSInvalidArgumentException', reason: '-[AppDelegate func5:]: unrecognized selector sent to instance 0x952b140'

what is the problem?

Answer 1

First, its a terrible thing to put methods like this on the app delegate, generally you want those methods in their own instances.

Second, AppDelegate must have

- (void)func5; 

declared in the header (that is AppDelegate.h)

From the code here I am assuming that by “instance” you mean your AppDelegate, and not something else like *MyMapClass myMap; thing.

If it is the second one then you have to make myMap a declared property in the header of the app delegate and then call it this way:

AppDelegate *delegate = (AppDelegate*) [[UIApplication sharedApplication] delegate];
[deletage.myMap func5];

and add the header in where you want to call the function.

#include AppDelegate.h 

STILL this is a terrible practice.