How to properly use a UIColor as a property

Question

Why is my color property always null?

@interface StreamingMediaControlButton : UIButton

@property (strong, nonatomic) UIColor *color;

@end

@implementation StreamingMediaControlButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        _color = [UIColor whiteColor];
    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    NSLog(@"color: %@", self.color);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, self.color.CGColor);
}
@end

How do you know it's always `null`? Also, now is it `color` or `iconColor`? — , Apr 23 '13 at 06:09
Set Break point on initWithFrame and Debug. It should go inside init Method. If its not going inside, your property will always be null. — βhargavḯ, Apr 23 '13 at 06:11
In 'init' methods you should avoid using getters and setters but assign it to the variable directly using '_color' — HAS, Apr 23 '13 at 13:05
@MikeWeller yes I chose to subclass UIButton instead of UIControl so I can place and size the control in interface builder. — TijuanaKez, Apr 25 '13 at 11:14
@MikeWeller Right. Only now I get "Unable to simultaneously satisfy constraints.". Any ideas why that would mess with the constraints? — TijuanaKez, Apr 25 '13 at 11:45
Does [this](http://stackoverflow.com/questions/14327145/unable-to-simultaneously-satisfy-constraints-no-constraints-in-place) or [that](http://stackoverflow.com/questions/15169158/unable-to-simultaneously-satisfy-constraints-when-animating) solve your problem? — HAS, Apr 25 '13 at 11:55

score 3 · Accepted Answer · answered Apr 25 '13 at 11:20

3

Your previous comment said you are using interface builder, which means a different init method is invoked on the button. You need to implement:

- (id)initWithCoder:(NSCoder *)decoder
{
    if ((self = [super initWithCoder:decoder])) {
        // setup code
    }

    return self;
}

Quite often it's good practice to implement both initWithCoder: and initWithFrame: and have them both call a commonInit method where your shared setup code goes.

answered Apr 25 '13 at 11:20

Mike Weller

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Just the act of implementing initWithCoder seems to call initWithFrame via [super init]; – TijuanaKez Apr 25 '13 at 11:39
initWithCoder seems to reset the view's frame property. Is this supposed to happen? The idea is to place and size the objects view in interface builder. This happens even if initWithFrame is not overridden. – TijuanaKez Apr 25 '13 at 11:57
....that would be because initWithCoder should call [super initWithCoder] not [super init]. Right. – TijuanaKez Apr 25 '13 at 12:22

score 0 · Answer 2 · answered Apr 23 '13 at 09:56

0

Try to Use Color RGB value instead of directly defining color that would be more effective.

answered Apr 23 '13 at 09:56

Mayur Prajapati

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As it will be a reusable interface control, I wanted to stick with UIColors. Ideally the control's color property would be set to a the chosen UIColor, but default to white. – TijuanaKez Apr 25 '13 at 11:18

How to properly use a UIColor as a property

2 Answers2