addTarget parentViewController and xcode warning me up than my selector is undeclared

Question

it is more curiosity than a real problem because it works. But i don't understand xcode warning. In my application I use addChildViewController so i have a child and a parent. In my child, I had a UIButton and i wanted to event a parent's function : it works but xcode says undeclared selector parentFunction :/ I can declare this function to erase this warning but it will be dead code (bad way). Or I can use a delegate, but why use delegate when you have a direct link.

[btn addTarget:self.parentViewController action:@selector(parentFunction:) forControlEvents:UIControlEventTouchUpInside];    //undeclared selector parentFunction

Best regards

Thx

cf http://stackoverflow.com/questions/18570907/should-i-fix-xcode-5-semantic-issue-undeclared-selector — Rich Tolley, Nov 30 '13 at 23:50

score 4 · Accepted Answer · answered Dec 01 '13 at 00:52

You need to import the parent view controller's .h file, and cast self.parentViewController to that class or the compiler doesn't know that method exists (since parentViewController returns a UIViewController, not your custom controller).

[btn addTarget:(ParentClass *)self.parentViewController action:@selector(parentFunction:) forControlEvents:UIControlEventTouchUpInside];

Replace ParentClass with whatever the class name of that parent is. Also, make sure that parentFunction: is implemented in the parent class (and has the colon), and is declared in its .h file.

thx (i forgot to import the header :/ and it does not come to mind as it worked) — Charlu, Dec 01 '13 at 01:09

addTarget parentViewController and xcode warning me up than my selector is undeclared

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