objective c – How to use typedef in dynamic properties? – Education Career Blog

It’s the first time I’m trying to use typedef. Admittedly I don’t have a very clear idea of what’s going on but my understanding was that the values inside typedef get assigned integers starting with 0. I’ve tried to use them as integers but I get various warnings and errors. One of them is “NSCFNumber objectForKey:: unrecognized selector sent to instance”. I don’t know how to troubleshoot this. I also haven’t written dynamic getters/setters much, so my approach might be wrong. Please help.

// MyView.h

typedef enum 
} MyShapeStyle;

@interface MyView : UIView
    MyShapeStyle shapeStyle;

    CALayer *myLayer;
    MyLayerDelegate *myLayerDelegate;

@property (nonatomic) MyShapeStyle shapeStyle;
@property (nonatomic, retain) CALayer *myLayer;
@property (nonatomic, retain) MyLayerDelegate *myLayerDelegate;


// MyView.m

#import "MyView.h"

@implementation MyView

@dynamic shapeStyle;
@synthesize myLayer;
@synthesize myLayerDelegate;

- (id)initWithFrame:(CGRect)frame 

    if ((self = super initWithFrame:frame)) 
        // Initialization code
        MyLayerDelegate *delegate = MyLayerDelegate alloc init;
        self.myLayerDelegate = delegate;

        CALayer *myLayer = CALayer layer;
        myLayer setDelegate:delegate;
        self.layer addSublayer:myLayer;
        self.myLayer = myLayer;
        self.shapeStyle = STYLE_C;

        delegate release;

    return self;

    return self.myLayer valueForKey:@"style" integerValue;

- (void)setShapeStyle:(MyShapeStyle)style
    self.myLayer setValue:NSNumber numberWithInt:style forKey:@"style";

// MyLayerDelegate.m

-(void)drawLayer:(CALayer *)theLayer inContext:(CGContextRef)theContext

    int id = theLayer valueForKey:@"style" integerValue;

   if( id == STYLE_A )
   }else if ( id == STYLE_B ){



There is no reason to use valueForKey: in that code; just get/set the various properties directly.

    return (MyShapeStyle) self.myLayer.style;

There is also no need for the @dynamic in that code. That is only needed if you are going to dynamically generate the methods.

As for why the objectForKey: does-not-respond error, there isn’t anything in that code that should trigger that. Could be a retain/release issue or it could be a problem in some other code that you haven’t shown.

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