You will want to declare a delegate protocol for your class. An example of a delegate protocol and interface for class Foo
might look like this:
@class Foo;
@protocol FooDelegate <NSObject>
@optional
- (BOOL)foo:(Foo *)foo willDoSomethingAnimated:(BOOL)flag;
- (void)foo:(Foo *)foo didDoSomethingAnimated:(BOOL)flag;
@end
@interface Foo : NSObject {
NSString *bar;
id <FooDelegate> delegate;
}
@property (nonatomic, retain) NSString *bar;
@property (nonatomic, assign) id <FooDelegate> delegate;
- (void)someAction;
@end
Don't forget to synthesize your properties in the @implementation
.
What this code did was declare a protocol called FooDelegate; a class that conforms to this protocol would be declared like @interface SomeClass : SuperClass <FooDelegate> {}
. Because this class conforms to the protocol FooDelegate
, it now gets to implement the methods under FooDelegate
(to require that these be implemented, use @required
instead of @optional
). The last step is for a Foo
object to be instantiated in the class that conforms to FooDelegate
, and for this Foo
object to have its delegate property set:
Foo *obj = [[Foo alloc] init];
[obj setDelegate:self];
Now, your class is prepared to receive messages from Foo
objects that have their delegates set correctly.
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