使用用户定义的运行时属性的UIView Shadow [英] UIView Shadow using User Defined Runtime Attributes

问题描述

使用用户定义的运行时属性"时，很难显示阴影.

I'm having a hard time getting a drop shadow to show when I am using "User Defined Runtime Attributes".

如下所示，如果我使用代码，这似乎完全可以正常工作.

It seems to work completely fine if I use code, as follows.

func formatView(view: UIView, cornerRadius: Bool) {

    if (cornerRadius) {view.layer.cornerRadius = 12 }
    view.layer.shadowColor = UIColor.black.cgColor
    view.layer.shadowOffset = CGSize.zero
    view.layer.shadowRadius = 3
    view.layer.shadowOpacity = 0.3
}

但是当我尝试使用用户定义的运行时属性时，它不再显示.这些是我目前正在使用的.

But when I try it with User Defined Runtime Attributes it doesn't show anymore. These are the ones I'm currently using.

唯一奇怪的是，如果我删除了 layer.shadowColor 属性，那么它似乎又可以工作了.但是我再也无法控制颜色了.它似乎默认为黑色，但是如果我决定选择灰色，则无法更改它.

The only thing that is weird is if I remove the layer.shadowColor attribute, then it seems to work again. But I can no longer control the color. It seems to default to black, but if I ever decide to choose a grey color instead, I wouldn't be able to change it.

这是因为Color属性是UIColor，shadowColor需要CGColor吗?

Is this because the Color Attribute is a UIColor and shadowColor expects a CGColor?

推荐答案

确实如您所说，因为用户定义的运行时属性"面板中的"<颜色>颜色" 类型创建了一个"<颜色> UIColor" ，但 layer.borderColor 保留 cgColor 类型.

It is indeed as you stated because the Color type in the User Defined Runtime Attributes panel creates a UIColor, but layer.borderColor holds a cgColor type.

您可以通过创建一个类别来解决此问题，该类别允许通过Interface Builder设置代理颜色:

You could solve this by creating a category that allows a proxy color to be set through Interface Builder:

extension CALayer {
    var borderUIColor: UIColor {
        set {
            self.borderColor = newValue.cgColor
        }

        get {
            return UIColor(cgColor: self.borderColor!)
        }
    }
}

但是，更好的方法是使用 IBDesignable 代替用户定义的运行时属性.

But a much nicer way is to use IBDesignable instead of User Defined Runtime Attributes, it is more clear.

您可以通过在项目中添加一个名为UIViewExtentions.swift的新swift文件(或将其粘贴到任何文件中)来实现此目的:

You do this by adding a new swift file named UIViewExtentions.swift in your project (or just paste this in any file) :

import UIKit

@IBDesignable extension UIView {
    @IBInspectable var borderColor:UIColor? {
        set {
            layer.borderColor = newValue!.cgColor
        }
        get {
            if let color = layer.borderColor {
                return UIColor(cgColor:color)
            }
            else {
                return nil
            }
        }
    }
    @IBInspectable var borderWidth:CGFloat {
        set {
            layer.borderWidth = newValue
        }
        get {
            return layer.borderWidth
        }
    }
    @IBInspectable var cornerRadius:CGFloat {
        set {
            layer.cornerRadius = newValue
            clipsToBounds = newValue > 0
        }
        get {
            return layer.cornerRadius
        }
    }
}

然后将在Interface Builder中为实用工具面板> Attributes Inspector中的每个按钮，imageView，标签等提供可用的

Then this will be available in Interface Builder for every button, imageView, label, etc. in the Utilities Panel > Attributes Inspector:

现在，如果您在属性"检查器中设置值并回顾用户定义的运行时属性"，您会看到它们会自动为您淘汰！

Now if you set you values in the Attributes Inspector and look back at the User Defined Runtime Attributes, you'll see they are automatically filed out for you!

有关更多信息，请参见: http://nshipster.com/ibinspectable-ibdesignable/

For more, see: http://nshipster.com/ibinspectable-ibdesignable/

这篇关于使用用户定义的运行时属性的UIView Shadow的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！