NSSelectorFromString

Question

Is there something wrong with this code? I'm trying to set up some buttons by defining at run time the label, the callback selector, and, later, a pointer to the UIButton itself. But with this code, I get EXC_BAD_ACCESS. It gos away if I delete the line with NSSelectorFromString. But since this is just an object being added to the dictionary, I don't understand shy it fails.

NSMutableDictionary *attachButtonDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                        @"Attach To Job",@"keyForLabel",
                                        NSSelectorFromString(@"attachToJob"), @"keyForSelector",
                                        nil];

Answer 1

a selector is not an objc object; a selector is an opaque representation of a method name.

the program will crash when adding it to the dictionary because it cannot be messaged. for example, it cannot be retained when added.

Answer 2

You cannot store the selector into your NSDictionary.

Just store the string and when you build your button call NSSelectorFromString().

Best, Christian

Edit:

NSMutableDictionary *attachButtonDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                                @"Attach To Job",@"keyForLabel",
                                                @"attachToJob", @"keyForSelector",
                                                nil];

UIButton *fancyButton = [[UIButton alloc] init];
[fancyButton addTarget:self action:NSSelectorFromString([attachButtonDictionary objectForKey:@"keyForSelector"]) forControlEvents:UIControlEventTouchUpInside];