swift - 使用 SF 符号时调整 UImage 的大小 - UIImage(systemName:)

Question

我有以下预打包的系统 SF 映像：

UIImage(systemName: "location.fill")

这可能看起来微不足道，但我怎样才能调整它以使其更大？谢谢你。

Answer 1

您可以实例化一个UIImage.SymbolConfiguration. 例如，您可以指定磅值：

let configuration = UIImage.SymbolConfiguration(pointSize: 24)
let image = UIImage(systemName: "location.fill", withConfiguration: configuration)

或者UIFont.TextStyle：

let configuration = UIImage.SymbolConfiguration(textStyle: .title1)
let image = UIImage(systemName: "location.fill", withConfiguration: configuration)

使用后一种方法，它将尊重设备上的可访问性文本大小设置。

Answer 2

下面的代码提供了两种方法：

1. UIKit 建议的方式（参见developer.apple.com/documentation）。在这里，您将 SF Symbol 图像视为字体并对其应用磅值。

2. 一种 SwiftUI 方式。按钮（以及示例中的一些相关文本）缩放到提供的框架。

       import UIKit
       import SwiftUI
   
       class SwiftUIButton : ObservableObject {
   
             @Published var state : Bool = true { didSet { buttonDidChange(state) } }
   
             private lazy var viewController = UIHostingController(rootView: SwiftCustomButton(delegate: self))
             var view : UIView { guard let view = viewController.view else {
                   preconditionFailure("*Fatal Error* Could not create SwiftUI button") }
                   return view
             }
   
             typealias typeForAction = () -> Void
             var action : typeForAction?
   
             func buttonDidChange(_ state : Bool) {
                   guard let action = action else {
                         return
                   }
                   action()
             }
       }
   
       struct SwiftCustomButton : View {
   
             @ObservedObject var delegate : SwiftUIButton
   
             var body : some View {
                   VStack() {
                         Button(action: {
                               self.delegate.state = !self.delegate.state
                         }) { Image(systemName: "gear")
                               .resizable()
                               .aspectRatio(contentMode: .fit)
                         }
   
                         Text(delegate.state ? "Hello" : "Goodbye")
                   }
             }
       }
   
   
       class ViewController: UIViewController {
   
             override func viewDidLoad() {
                   super.viewDidLoad()
   
                   let button = SwiftUIButton()
                   button.action = { print("In the ViewController the button has changed to: \(button.state)")}
                   button.view.frame = CGRect(x: 200, y: 200, width: 80, height: 80)
                   view.addSubview(button.view)
   
                   let image = UIImage(systemName: "gear")
                   let symbolConfiguration = UIImage.SymbolConfiguration(pointSize: 64.0)
   
                   let adjustedImage = image?.applyingSymbolConfiguration(symbolConfiguration)
   
                   let uButton = UIButton(type: .custom)
                   uButton.setImage(adjustedImage , for: .normal)
                   uButton.frame = CGRect(x: 20, y: 200, width: 80, height: 80)
                   uButton.target(forAction: #selector(self.buttonAction), withSender: uButton)
                   view.addSubview(uButton)
   
                   self.view = view
             }
   
             @objc func buttonAction() {
                   print("UIButton pressed")
             }
       }