如何在Interface Builder中使用自定义UIButton类别？

I'm coding a simple card game for my younger sister on a whim. I'm using UIButtons: default state is face down, selected state is face up. I need the buttons to have a boolean property that tells me if they've ever been flipped over. If not, it gets set to true (that way I'm not just drawing random cards on each flip). I tried creating a category of UIButton called CardGameButton. In the .h file:

我一时兴起为我的妹妹编写一个简单的纸牌游戏。我正在使用UIButtons：默认状态是面朝下，选择状态正面朝上。我需要按钮有一个布尔属性，告诉我它们是否曾被翻过来。如果没有，它被设置为true（这样我不只是在每次翻转时绘制随机卡）。我尝试创建一个名为CardGameButton的UIButton类。在.h文件中：

@interface UIButton (CardGameButton)
@property (nonatomic) BOOL discovered;
@end

In the .m file:

在.m文件中：

@implementation UIButton (CardGameButton)
@dynamic discovered;
@end

This is really all I need. How do I use this in IB? I have a bunch of UIButtons on a screen that I want to be CardGameButtons. But when I try to switch my calls to UIButton in my view controller to CardGameButton, it tells me CardGameButton isn't a type (yes I imported the file). And when I try to switch the class of the UIButtons in the storyboard to CardGameButtons, the console tells me that they're an "unknown class". I tried subclassing UIButton, but that didn't work (I just need them to be RoundedRectButtons with the extra property, and since you can't subclass RoundedRectButton they wouldn't display properly). How do I make this work in IB?

这就是我真正需要的。我如何在IB中使用它？我在屏幕上有一堆UIButtons，我想成为CardGameButtons。但是当我尝试将我的视图控制器中的UIButton调用切换到CardGameButton时，它告诉我CardGameButton不是一个类型（是的，我导入了文件）。当我尝试将故事板中的UIButtons类转换为CardGameButtons时，控制台告诉我它们是一个“未知类”。我尝试了子类化UIButton，但是这不起作用（我只需要它们是带有额外属性的RoundedRectButtons，因为你不能将RoundedRectButton子类化，它们将无法正确显示）。我如何在IB中完成这项工作？

2 个解决方案

#1

You're treating CardGameButtons as though it's a subclass of UIButton when instead it's a category. Anything you declare as UIButton will have the discovered property as standard, but you can't 'create' a CardGameButtons as it's not a thing in itself.

您将CardGameButtons视为UIButton的子类，而不是它是一个类别。你声明为UIButton的任何东西都会将已发现的属性作为标准，但是你不能“创建”一个CardGameButtons，因为它本身并不是一件事。

#2

Categories are not types. They're just used to add some extended behavior to the class.

类别不是类型。它们只是用来为类添加一些扩展行为。

I suggest that you try subclassing UIButton and call it CardGameButton. Add the BOOL property to its interface. You can still make it a round rect button, by setting buttonType to UIButtonTypeRoundedRect "round rect buttons aren't a separate subclass.". Then override

我建议您尝试继承UIButton并将其称为CardGameButton。将BOOL属性添加到其接口。您仍然可以将它设置为圆形矩形按钮，方法是将buttonType设置为UIButtonTypeRoundedRect“圆形矩形按钮不是单独的子类。”。然后覆盖

- (void)sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {
    if(event.type == UIEventTypeTouches){
        self.discovered = YES; // or handle the logic as you want here
    }
    [super sendAction:action to:target forEvent:event];
}

You can add a UIButton to your view from the IB, and then its class to your created subclass and set its type to round rect.

您可以从IB中将UIButton添加到视图中，然后将其类添加到创建的子类中，并将其类型设置为round rect。

Edit: As you stated, buttonType is actually readOnly, so we can't use that to draw a round rect button. However, it turns out that it's not hard to draw it.

编辑：如你所说，buttonType实际上是readOnly，所以我们不能用它来绘制一个圆形的矩形按钮。但事实证明，绘制它并不难。

Check this tutorial. It shows how to do it using CALayer property of UIButton and using UIBezeirPath.

查看本教程。它显示了如何使用UIButton的CALayer属性并使用UIBezeirPath来完成它。

#1

#2