No known class method for selector 'circleOfBu

A function circleOfButtons:buttonSize:radius: in SGView (below) is called from ParentView and I want ParentView to define the values inside SGView whenever ParentView sends a message to SGView.

This is the implementation file.

#import <UIKit/UIKit.h>
#import “ParentView.h"
#import "SGView.h"

@implementation ParentView : UIView

- (id)initWithFrame:(CGRect)frame {
    self                        = [super initWithFrame:[UIScreen mainScreen].bounds];
    if (self) {

    self.backgroundColor        = [UIColor lightGrayColor];

    int     count               = 5;
    CGFloat size                = 80.0;
    CGFloat radius              = 68;

    SGView *myView              = [SGView circleOfButtons:count buttonSize:size radius:radius];
    [self addSubview:myView];
    }
return self;
}

SGView arranges multiple UIButtons in a circle and is essentially like this

#import "SGView.h"

@implementation SGView : UIView

+(id)circleOfButtons:(int)buttonCount buttonSize:(CGFloat)buttonSize circleRadius:(CGFloat)circleRadius
    {
    UIView *multipleViews       = [self new];

    // … circular geometry …
    [multipleViews addSubview:circleButton];
    }
    return multipleViews;
}
@end

The error message - at the line SGView *myView - is:

No known class method for selector 'circleOfButtons:buttonSize:radius:'

My guess is the compiler wants a declaration in the interface. I’m working through these tutorials trying to decide what the interface file should look like and though there are 6 SO questions that may already have answered my question, only this one had an example that seemed vaguely relevant.

This is my interface file.

#import <UIKit/UIKit.h>
#import "ViewController.h"
#import "SGView.h"

@interface ParentView : UIView {
}

+(id)circleOfButtons:(int)buttonCount buttonSize:(CGFloat)buttonSize circleRadius:(CGFloat)circleRadius;

@end

Can anyone please give an example showing what this interface file should look like ? Thanks.

UPDATE

Here is SGView.h (revised)

#import <UIKit/UIKit.h>
@interface SGView : UIView {
}
+(id)circleOfButtons:(int)buttonCount buttonSize:(CGFloat)buttonSize circleRadius:(CGFloat)circleRadius;
@end

I also noticed if the statement

        SGView *myView              = [SGView circleOfButtons:count buttonSize:size radius:radius];

is changed to

        SGView *myView              = [self circleOfButtons:count buttonSize:size radius:radius];

the error changes to

No visible @interface for 'ParentView' declares the selector 'circleOfButtons:buttonSize:radius:'

it was previously

No known class method for selector 'circleOfButtons:buttonSize:radius:'

回答1:

You are calling

  SGView *myView              = [SGView circleOfButtons:count buttonSize:size radius:radius];

It should be

SGView *myView              = [SGView circleOfButtons:count buttonSize:size circleRadius:radius];

回答2:

Declare +(id)circleOfButtons:(int)buttonCount buttonSize:(CGFloat)buttonSize circleRadius:(CGFloat)circleRadius in SGView.h file. Now you will get the method in ParentView class.

Happy coding :) .