Passing a selector name as a method parameter

0
votes

I'm writing a custom helper method that will get used a lot and return several buttons. Each button will of course have its own target selector when pressed, and I want to pass the selector as a parameter into this method so the returned button has the specified selector.

But I'm not sure how to pass a selector as a method parameter. Something like this:

-(returnedInstance)someMethod:(WhatClass?*)selectedFunction{

[SomeClassWithASelectorParameter method:whatever selector:@selector(selectedFunction)];

}

where selectedFunction is a parameter passed into the method.

I tried making WhatClass?* a NSString and also SEL but that resulted in:

[NSInvocation invocationWithMethodSignature:]: method signature argument cannot be nil

2
objective-cselectornsinvocation
use SEL to pass the selector. and remove @selector(..) just use selectedFunction. – HelmiB

2 Answers

4
votes

Why don't you just pass a SEL? i.e. a selector. Like so:

-(returnedInstance)someMethod:(SEL)selectedFunction{
    [SomeClassWithASelectorParameter method:whatever selector:selectedFunction];
}

Alternatively, NSSelectorFromString:

-(returnedInstance)someMethod:(NSString*)selectedFunction{
    [SomeClassWithASelectorParameter method:whatever selector:NSSelectorFromString(selectedFunction)];
}
1
votes

You want to use SEL, and when you refer to it, you don't have to use selector:

-(returnedInstance)someMethod:(SEL)selectedFunction{

    [SomeClassWithASelectorParameter method:whatever selector:selectedFunction];

}