Selector function with int parameter?

Using Cocos2d-iphone, and objective-c game development framework.

I create a button with:

CCMenuItemImage *slot = [CCMenuItemImage itemFromNormalImage:@"BattleMoveSelectionSlot1.png" 
                                                       selectedImage:@"BattleMoveSelectionSlot2.png"
                                                              target:self selector:@selector(moveChosen:i)];

And my moveChosen method is:

-(void)moveChosen:(int)index {

}

However, for some reason I get an error on @selector(moveChosen:i) where i is an integer. How, then开发者_JAVA百科, may I pass an integer parameter to my function when the button is pressed?

The error is

Expected ':'

Georg is correct. Note that as implemented, this will invoke undefined behaviour since index is an int but the action method it's being used as expects an object (id) there, not an int. The signature of an action method is:

- (void)methodName:(id)sender;

Or, when used with Interface Builder:

- (IBAction)methodName:(id)sender;

(IBAction is an alias of void. The two are semantically different but functionally identical.)

Where sender is the object that sent the action message--in this case, the object you created and assigned to the slot variable.

You don't include any argument names in the selector:

@selector(moveChosen:)

Selectors don't allow for binding parameters.

Georg is partially correct. For your example, it would be:

@selector(moveChosen:)

But note: if you have more than one parameter, you do include the formal parameter names to get the selector. If your function signature were:

- (void)moveChosen:(int)index withThing:(Thing*)thing

then the selector would be:

@selector(moveChosen:withThing:)

The selector is just the name of the message that you want to send. The arguments will be provided when it is called — which means CCMenuItemImage will decide what argument is passed. If CCMenuItemImage does not support providing an integer parameter, you can't make it do that.