缩小UILabels的质量

Question

我使用Swift 3创建一个iOS界面，其中某些UIView包含（其中包括）UILabel s根据它们在屏幕上的位置放大和缩小。我的第一个方法是创建一个舒适的大尺寸（比如100x100）并填充视图，然后根据需要使用CGAffineTransform(scaleX:y:)进行缩放，但是我注意到标签中文本的缩小比例并不优雅，而且文本变得像素化并且在小尺度下接近不可读。作为比较（参见下面的示例），直接更改字体大小会得到更好的结果，但是我的视图中的结构有些复杂，并且不得不根据某个大小因素重新绘制所有内容，这将是一件麻烦事。有没有更好更平滑的方法来解决这个问题？

下面是我创建的一个示例项目，用于说明问题以及模拟器中的输出（与iPhone本身相同），缩小视图位于左侧（红色），更改的字体大小是右侧（绿色）。

class ViewController: UIViewController { 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view, typically from a nib. 

     for i in 1...10 { 
      let f = CGFloat(1.0)/CGFloat(i) 
      let view1 = UIView(frame: CGRect(x: 0, y: 0, width: 150, height: 50)) 
      view1.backgroundColor = UIColor.red 
      let label1 = UILabel(frame: CGRect(x: 0, y: 0, width: 150, height: 50)) 
      label1.text = "\(100/i)%" 
      label1.font = UIFont(name: "Verdana", size: 24.0) 
      label1.textAlignment = .right 
      view1.addSubview(label1) 
      view1.transform = CGAffineTransform(scaleX: f, y: f) 
      view1.center = CGPoint(x: 160 - 75.0 * f, y: CGFloat(60 * i) + 25.0 * f) 
      self.view.addSubview(view1) 

      let view2 = UIView(frame: CGRect(x: CGFloat(170), y: CGFloat(60 * i), width: 150 * f, height: 50 * f)) 
      view2.backgroundColor = UIColor.green 
      let label2 = UILabel(frame: CGRect(x: 0, y: 0, width: 150 * f, height: 50 * f)) 
      label2.text = "\(100/i)%" 
      label2.font = UIFont(name: "Verdana", size: 24.0 * f) 
      view2.addSubview(label2) 
      self.view.addSubview(view2) 

     } 

    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 


} 

Answer 1

这可能一个答案 - 但不是真的适合评论，所以...

试试这个 - 它创造的黄色第三届“栏” - 背景视图，使用.adjustsFontSizeToFitWidth。字体大小将根据包含标签的视图的大小自动调整。

override func viewDidLoad() { 
    super.viewDidLoad() 
    // Do any additional setup after loading the view, typically from a nib. 

    for i in 1...10 { 
     let f = CGFloat(1.0)/CGFloat(i) 
     let view1 = UIView(frame: CGRect(x: 0, y: 0, width: 150, height: 50)) 
     view1.backgroundColor = UIColor.red 
     let label1 = UILabel(frame: CGRect(x: 0, y: 0, width: 150, height: 50)) 
     label1.text = "\(100/i)%" 
     label1.font = UIFont(name: "Verdana", size: 24.0) 
     label1.textAlignment = .right 
     view1.addSubview(label1) 
     view1.transform = CGAffineTransform(scaleX: f, y: f) 
     view1.center = CGPoint(x: 160 - 75.0 * f, y: CGFloat(60 * i) + 25.0 * f) 
     self.view.addSubview(view1) 

     let view2 = UIView(frame: CGRect(x: CGFloat(170), y: CGFloat(60 * i), width: 150 * f, height: 50 * f)) 
     view2.backgroundColor = UIColor.green 
     let label2 = UILabel(frame: CGRect(x: 0, y: 0, width: 150 * f, height: 50 * f)) 
     label2.text = "\(100/i)%" 
     label2.font = UIFont(name: "Verdana", size: 24.0 * f) 
     view2.addSubview(label2) 
     self.view.addSubview(view2) 

     let view3 = UIView(frame: CGRect(x: CGFloat(270), y: CGFloat(60 * i), width: 150 * f, height: 50 * f)) 
     view3.backgroundColor = UIColor.yellow 
     let label3 = UILabel(frame: view3.bounds) 
     label3.text = "\(100/i)%" 
     label3.font = UIFont(name: "Verdana", size: 24.0) 
     label3.adjustsFontSizeToFitWidth = true 
     label3.minimumScaleFactor = 0.05 
     label3.numberOfLines = 0 
     // we want the label to resize with the view, if the view frame changes 
     label3.autoresizingMask = [.flexibleWidth, .flexibleHeight] 
     view3.autoresizesSubviews = true 
     view3.addSubview(label3) 
     self.view.addSubview(view3) 

    } 
}