Re: NSInvocation problem

FROM : Sherm Pendley
DATE : Wed Nov 24 22:20:32 2004

On Nov 24, 2004, at 4:08 PM, <email_removed> wrote:

> I have a small problem with NSInvocation, im setting an invocation up
> like this:
>
> // setWidth: is a method defined by self.
>
> NSMethodSignature*    sig = [LayoutControl
> instanceMethodSignatureForSelector: @selector(setWidth:)];
> NSInvocation*        incovation = [NSInvocation
> invocationWithMethodSignature:sig];
> [invocation setSelector: @selector(setWidth:)];
> [invocation setTarget:self];
>
> whenever i try and invoke it, i get this error message:
>
> 2004-11-24 16:04:04.970 Cocode[4943] *** -[NSInvocation
> copyWithZone:]: selector not recognized
>
> Whats going n here and how can i fix it?


As evidenced by the ':' at the end, setWidth: takes a parameter, but
the code above doesn't provide that parameter to the invocation.

For example, if width is a float:

float newWidth = 0.0;
[invocation setArgument:&newWidth atIndex:2];

(Indexes 0 and 1 are always target & selector, respectively.)

sherm--

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