自定义 UILabel 视图未更新其在 Interface Builder 中的框架

Question

我正在尝试为 Font Awesome 创建一个 UILabel，到目前为止它似乎运行良好。我遇到的问题是，当我在 prepareForInterfaceBuilder() 中更改标签的字体大小时，它没有反映在 Interface Builder 中。

这是我的代码：

import Foundation
import UIKit

@IBDesignable
class FALabel : UILabel {

    @IBInspectable
    private var icon: String = ""

    @IBInspectable
    private var weight: NSInteger = 0

    /**
     * The type for the Font Awesome Label
     */
    enum FAType {
        case Brands
        case Light
        case Regular
        case Solid
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupView()
    }

    /**
     * Prepare the view or the Interface Builder.
     */
    override func prepareForInterfaceBuilder() {
        super.prepareForInterfaceBuilder()
        setupView()
    }

    /**
     * Set up the view.
     */
    func setupView() {
        let type: FAType =  {
            switch self.weight {
            case 0:  return .Light
            case 2:  return .Solid
            case 3:  return .Brands
            default: return .Regular
            }
        }()

        setFontAwesomeIcon(faType: type, size: self.font.pointSize, icon: FAIcons.iconNamed(name: self.icon))
        self.sizeToFit()
        self.frame = CGRect(x: self.frame.minX, y:self.frame.minY, width:self.frame.width, height:self.frame.height)
        self.invalidateIntrinsicContentSize()
    }

    /**
     * Calculate the intrinsic content size.
     */
    override var intrinsicContentSize: CGSize {
        return CGSize(width: self.frame.width, height: self.frame.height)
    }

    /**
     * Set the Font Awesome Icon for the label.
     *
     * - parameter fatype: The type to set.
     * - parameter size:   The size for the font.
     * - parameter icon:   The icon to use.
     */
    func setFontAwesomeIcon(faType: FAType, size: CGFloat, icon:String) {
        if faType == .Regular {
            self.font = UIFont(name: "FontAwesome5Pro-Regular", size: size)
        } else if faType == .Solid {
            self.font = UIFont(name: "FontAwesome5Pro-Solid", size: size)
        } else if faType == .Light {
            self.font = UIFont(name: "FontAwesome5Pro-Light", size: size)
        } else if faType == .Brands {
            self.font = UIFont(name: "FontAwesome5Brands-Regular", size: size)
        }
        self.text = icon
    }
}

当我在 Interface Builder 中更改任何内容时，框架似乎保持相同大小，但图标本身绘制得比我想要的更大。

我认为从 prepareForInterfaceBuilder() 调用 self.sizeToFit() 应该调整视图大小并更改那些 15x18 尺寸，但它似乎不是。

Answer 1

我认为任何与尺寸相关的调整都应该放在 layoutSubviews。

override func layoutSubviews() {
   super.layoutSubviews()
   setupView()
}

您可以使用 prepareForInterfaceBuilder 填充一些示例数据，例如在 IB 中预览，但您不应该回忆起您已经在 init 方法中完成的设置（例如 setupView()).

您也可以省略我猜想的 init 方法并将所有内容简化为：

import Foundation
import UIKit

@IBDesignable
class FALabel : UILabel {

    @IBInspectable
    public var icon: String = "" { 
        didSet { setupView() } 
    }

    @IBInspectable
    public var weight: NSInteger = 0 { 
        didSet { setupView() } 
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        setupView()
    }

    /**
     * The type for the Font Awesome Label
     */
    enum FAType {
        case Brands
        case Light
        case Regular
        case Solid
    }

    /**
     * Set up the view.
     */
    func setupView() {
        let type: FAType =  {
            switch self.weight {
            case 0:  return .Light
            case 2:  return .Solid
            case 3:  return .Brands
            default: return .Regular
            }
        }()

        setFontAwesomeIcon(faType: type, size: self.font.pointSize, icon: FAIcons.iconNamed(name: self.icon))
        self.sizeToFit()
        self.frame = CGRect(x: self.frame.minX, y:self.frame.minY, width:self.frame.width, height:self.frame.height)
        self.invalidateIntrinsicContentSize()
    }

    /**
     * Calculate the intrinsic content size.
     */
    override var intrinsicContentSize: CGSize {
        return CGSize(width: self.frame.width, height: self.frame.height)
    }

    /**
     * Set the Font Awesome Icon for the label.
     *
     * - parameter fatype: The type to set.
     * - parameter size:   The size for the font.
     * - parameter icon:   The icon to use.
     */
    func setFontAwesomeIcon(faType: FAType, size: CGFloat, icon:String) {
        if faType == .Regular {
            self.font = UIFont(name: "FontAwesome5Pro-Regular", size: size)
        } else if faType == .Solid {
            self.font = UIFont(name: "FontAwesome5Pro-Solid", size: size)
        } else if faType == .Light {
            self.font = UIFont(name: "FontAwesome5Pro-Light", size: size)
        } else if faType == .Brands {
            self.font = UIFont(name: "FontAwesome5Brands-Regular", size: size)
        }
        self.text = icon
    }
}