Re: new to cocoa
Re: new to cocoa
- Subject: Re: new to cocoa
- From: Kiel Gillard <email@hidden>
- Date: Fri, 14 May 2010 14:38:25 +1000
On 12/05/2010, at 6:36 AM, Alejandro Marcos Aragón wrote:
> Hi all,
>
> I'm new to Cocoa, and I couldn't find information about an error that I'm getting on the web. I'm trying to create an NSMutableDictionary where the keys are of type UIButton*:
>
>
> // create button for unit
> UIButton* unitButton = [[UIButton alloc] init];
> [sourceButtonMap setObject:[NSString stringWithString:@"no"] forKey:unitButton];
>
> Of course, the sourceButtonMap is defined in the class and initialized in the init function as sourceButtonMap = [[NSMutableDictionary alloc] init];
>
> The error I get when I try to add the key-value pair is:
>
> *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[UIButton copyWithZone:]: unrecognized selector sent to instance 0x3931e90'
>
> Is this happening because I can't store UIButton* as keys?
Welcome to iPhone OS development!
This most certainly is happening because you cannot use UIButton objects as keys in a dictionary because NSDictionary copies the objects used as keys. Furthermore, UIButton does implement the NSCopying methods.
> Can anyone point me why I'm getting this error? Thank you all,
<http://developer.apple.com/mac/library/documentation/Cocoa/Reference/Foundation/Classes/NSDictionary_Class/Reference/Reference.html>
See the second paragraph of the section titled "Overview".
I suggest you revise your design. I don't know exactly what you're trying to do. Perhaps @"no" should be the key for the UIButton?
Kiel
>
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| | >new to cocoa (From: Alejandro Marcos Aragón <email@hidden>) |