无法实现UIView子类

Question

I am trying to create a UIView which is basically a number with a circular background. I am using a UIView and applying a corner radius of half the dimension for the circle. Then I am adding the number as a UILabel subview to the above view.

What I want is close to this (without the fancy border): (This is a screenshot from the app Count Battle).

Please help me rewrite by moving the code under the proper methods (drawrect, init, layoutSubviews, or any custom method). This is the code in it's current form. I think my understanding of this thing is muddled up, and this just doesn't look right.

This is the header file:

//  CircleNumView.h

#import <UIKit/UIKit.h>

@interface CircleNumView : UIView

@property (nonatomic, strong) UIColor *circleColor;

- (instancetype)initWithRadius:(CGFloat)radius
                        center:(CGPoint)center
                          text:(NSString *)text;

@end

This is the implementation file:

//  CircleNumView.m

#import "CircleNumView.h"

@interface CircleNumView ()

@property (nonatomic) CGFloat radius;
@property (nonatomic, strong) NSString *text;

@end


@implementation CircleNumView

// designated initializer
- (instancetype)initWithRadius:(CGFloat)radius
                        center:(CGPoint)center
                          text:(NSString *)text
{
    self = [super init];

    self.radius = radius;
    self.text = text;
    self.frame = CGRectMake ( center.x - radius, center.y - radius, 2 * radius, 2 * radius);

    self.circleColor = [UIColor whiteColor];

    self = [self createView];

    return self;
}


- (CircleNumView *)createView
{
    CircleNumView *circularView = [[UIView alloc] initWithFrame:self.frame];

    circularView.backgroundColor = self.circleColor;

    UILabel *label = [[UILabel alloc] initWithFrame:circularView.bounds];
    label.text = self.text;
    label.textColor = [UIColor blackColor];

    [circularView addSubview:label];

    circularView.clipsToBounds = YES;
    circularView.layer.cornerRadius = self.radius;

    [self addSubview:circularView];

    return circularView;
}

@end

Answer 1

You were doing everything pretty well until that self = [createView];

This is the implementation file that I would write:

//
//  CircleNumberView.m
//  
//
//  Created by James Valaitis on 13/04/2014.
//
//

#import "CircleNumberView.h"

#pragma mark - Circle Number View Private Class Extension

@interface CircleNumberView ()

/** The radius of this circular view.   */
@property (nonatomic, assign)       CGFloat             radius;
/** The number to present encapsulated as a string. */
@property (nonatomic, copy)         NSString            *text;
/** The label that shows the number contents of this view.  */
@property (nonatomic, strong)       UILabel             *textLabel;

@end

#pragma mark - Circle Number View Implementation

@implementation CircleNumberView

#pragma mark - Initialisation

/**
 *  Initialises a circlular view with a number in the middle.
 *
 *  @param  radius                  The radius of the circle.
 *  @param  center                  The center point of the circle in it's superview.
 *  @param  text                    The number as a string to present in the middle of this view.
 *
 *  @return An initialized object.
 */
- (instancetype)initWithRadius:(CGFloat)radius center:(CGFloat)center text:(NSString *)text
{
    CGRect frame = CGRectMake(center.x - radius, center.y - radius, radius * 2, radius * 2);

    if (self = [super initWithFrame:frame])
    {
        _radius = radius;
        _text = text;

        [self configureViewAndSubviews];
    }

    return self;
}

#pragma mark - Property Accessor Methods - Getters

/**
 *  The label that shows the number contents of this view.
 *
 *  @return The label that shows the number contents of this view.
 */
- (UILabel *)textLabel
{
    if (!_textLabel)
    {
        _textLabel = [[UILabel alloc] initWithFrame:self.bounds];
        _textLabel.numberOfLines = 0;
        _textLabel.textColor = [UIColor blackColor];
    }

    return _textLabel;
}

#pragma mark - Subview Management

/**
 *  Configures this view as well as it's subviews.
 */
- (void)configureViewAndSubviews
{
    self.backgroundColor = [UIColor whiteColor];
    self.clipsToBounds = YES;
    self.layer.cornerRadius = self.radius;

    self.textLabel.text = self.text;
    [self addSubview:self.textLabel];
}

@end