ios - IBDesignable 构建失败

Question

我已经创建了 IBDesignable 和 IBInspectable 自定义类来为 View 提供阴影和角半径

但是当我将 Designable 类分配给 view 时，我得到 Designable Build Failed

这是我的代码

import Foundation

import UIKit

@IBDesignable
class DesignableView: UIView {
}

@IBDesignable
class DesignableButton: UIButton {
}

@IBDesignable
class DesignableLabel: UILabel {
}

@IBDesignable
class DesignableTableView: UITableView {

}

extension UIView {

    @IBInspectable
    var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
        }
    }

    @IBInspectable
    var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable
    var borderColor: UIColor? {
        get {
            if let color = layer.borderColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.borderColor = color.cgColor
            } else {
                layer.borderColor = nil
            }
        }
    }

    @IBInspectable
    var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.shadowRadius = newValue
        }
    }

    @IBInspectable
    var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.shadowOpacity = newValue
        }
    }

    @IBInspectable
    var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            layer.shadowOffset = newValue
        }
    }

    @IBInspectable
    var shadowColor: UIColor? {
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.shadowColor = color.cgColor
            } else {
                layer.shadowColor = nil
            }
        }
    }
}

这是我得到的

Answer 1

第一次尝试:IBDesignable 构建失败

对我来说，当我将鼠标悬停在 InterfaceBuilder Designables: Build Failed 上时，它给出了一条错误消息，内容类似

Cannot find any source files for the declaration or ...

所以，我把它当作一个线索，比如 Xcode 无法索引我的自定义 UIView 类文件，所以我所做的就是退出 Xcode 并重新启动它，然后它索引了我的自定义 Swift类文件和 InterfaceBuilder 能够正确找到它。

首先尝试一下，然后转到其他选项!