Pressing UIBarButtonItem on a NavigationController

I've added a button the my navigation bar like so:

UIBarButtonItem *anotherButton = [[UIBarButtonItem alloc] initWithTitle:@"Edit" style:UIBarButtonItemStylePlain target:self action:@selector(methodtocall:)];          

self.navigationI开发者_如何学JAVAtem.rightBarButtonItem = anotherButton;
[anotherButton release];

However when I press this I get a InvalidArgumentException. This is in a brand new navigation project. Does anyone know why I get this behaviour?

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You need to define your action method like this:

-(void) methodtocall:(UIBarButtonItem *) sender {
   //do stuff...
}

You are probably getting an InvalidArgument error because you didn't define your method to receive the UIBarButtonItem.