自定义 UILabel 视图未在 Interface Builder 中更新其框架

Posted 2023-02-27

【中文标题】自定义 UILabel 视图未在 Interface Builder 中更新其框架

【英文标题】：Custom UILabel View not updating it's frame in Interface Builder

【发布时间】：2019-10-14 22:13:39

【问题描述】：

我正在尝试为 Font Awesome 创建一个 UILabel，目前它似乎运行良好。我遇到的问题是，当我更改 prepareForInterfaceBuilder() 中标签的字体大小时，它不会反映在 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，框架似乎保持相同的大小，但图标本身却像我想要的那样被绘制得更大。

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，但似乎并非如此。

【参考方案1】：

我认为任何尺寸相关的调整都应该放在layoutSubviews。

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

您可能会使用prepareForInterfaceBuilder 来填充一些样本数据，例如在 IB 中进行预览，但您不应该回忆您在 init 方法中所做的设置（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