为什么从自定义 UIView 向 UIButton 添加子视图不显示添加的子视图？

Question

我有一个 UIView 的子类，我是从一个 NIB 文件加载的。我的 NIB 文件，包含一个 UIButton 和一个 IBOutlet，称为 clock

@property (strong, nonatomic) IBOutlet UIButton *clock;

显示在我的界面构建器上的时钟按钮中设置的文本！但是我从 initWithCoder 添加的其他子视图没有。这是为什么呢？

.h 文件

@interface TWTimerView : UIView

@property (strong, nonatomic) IBOutlet UIButton *clock;

@property (strong, nonatomic) UIImageView *circle;
@property (strong, nonatomic) UIImageView *pointer;
@property (strong, nonatomic) UIImageView *tick;

@property (strong, nonatomic) UIImageView *circleGlow;
@property (strong, nonatomic) UIImageView *pointerGlow;
@property (strong, nonatomic) UIImageView *tickGlow;

@end

.m 文件

@implementation TWTimerView

-(id)initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];
    if(self) {

        self.backgroundColor = [UIColor clearColor];

        _circle  = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"circle"]];
        _pointer = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"pointer"]];
        _tick    = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tick"]];

        [_clock addSubview:_circle];
        [_clock addSubview:_pointer];
        [_clock addSubview:_tick];

    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{

    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        TWTimerView *view= [[[NSBundle mainBundle] loadNibNamed:@"TimerView" owner:self options:nil] objectAtIndex:0];
        [self addSubview:view];

    }
    return self;
}

@end

谢谢！

Answer 1

这是我要做的： 如果您不需要使用框架，请删除initWithFrame 方法并使用其他方法来帮助您加载视图，就像这样。

+ (id)loadViewFromNIBFile {
    NSArray * array = [[NSBundle mainBundle] loadNibNamed:@"TimerView" owner:self options:nil];
    //You may want to assert array only contains one element here
    TWTimerView * view = (TWTimerView *)[array objectAtIndex:0];
    NSAssert([view isKindOfClass:TWTimerView.class], @"Unexpected class");
    [view _setDefaultComponents];
    return view;
}

- (void)_setDefaultComponents {
    self.backgroundColor = [UIColor clearColor];
    _circle  = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"circle"]];
    _pointer = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"pointer"]];
    _tick    = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tick"]];
    [_clock addSubview:_circle];
    [_clock addSubview:_pointer];
    [_clock addSubview:_tick];
}

致电[TWTimerView loadViewFromNIBFile] 获取您的视图实例。

Answer 2

您的 TWTimerView 有一个笔尖，其中您有一个 UIButton？而且你有一个 UIView-Subclass，就是给你的 UIButton 添加三个 UIImageViews，你为什么要这样做？！

为什么不继承 UIButton 并在那里设置 UIImageViews？

我会把它改成这样：

@implementation TWTimerView

    - (id)initWithFrame:(CGRect)frame
    {

        self = [super initWithFrame:frame];
        if (self) {
            // Initialization code
            [[[NSBundle mainBundle] loadNibNamed:@"TimerView" owner:self options:nil] objectAtIndex:0];
            self.backgroundColor = [UIColor clearColor];

            _circle  = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"circle"]];
            _pointer = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"pointer"]];
            _tick    = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"tick"]];

            [_clock addSubview:_circle];
            [_clock addSubview:_pointer];
            [_clock addSubview:_tick];

        }
        return self;
    }

@end