[移动开发]Swift 之自定义 Toast

• 代码：

import Foundation
import UIKit

enum Toast {
  static func toast(at view: UIView, message: String, completion: (() -> Void)? = nil) {
    let toastLabel = MGSLabel(frame: .zero)
    toastLabel.text = "  \(message)  "
    toastLabel.numberOfLines = 0
    toastLabel.font = UIFont.systemFont(ofSize: 15.0)
    toastLabel.backgroundColor = UIColor(white: 0.0, alpha: 0.5)
    toastLabel.textColor = .white
    toastLabel.textAlignment = .center
    toastLabel.layer.cornerRadius = 7.0
    toastLabel.layer.masksToBounds = true
    toastLabel.textInsets = UIEdgeInsets(top: 5.0, left: 0, bottom: 5.0, right: 0)
    
    view.addSubview(toastLabel)
    toastLabel.setContentHuggingPriority(.init(rawValue: 750.0), for: .horizontal)
    toastLabel.snp.makeConstraints { make in
      make.center.equalToSuperview()
      make.leading.trailing.equalToSuperview().inset(10.0)
    }
    
    DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
      toastLabel.removeFromSuperview()
      completion?()
    }
  }
}

• 其中， MGSLabel 的代码为：
  主要功能：可以设置 UILabel 的上下左右间距

import Foundation
import UIKit

class MGSLabel: UILabel {
  var textInsets: UIEdgeInsets = .zero
  
  override func drawText(in rect: CGRect) {
    super.drawText(in: UIEdgeInsetsInsetRect(rect, textInsets))
  }
  
  override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
    let insets = textInsets
    var rect = super.textRect(forBounds: UIEdgeInsetsInsetRect(bounds, insets),
                              limitedToNumberOfLines: numberOfLines)
    
    rect.origin.x -= insets.left
    rect.origin.y -= insets.top
    rect.size.width += (insets.left + insets.right)
    rect.size.height += (insets.top + insets.bottom)
    return rect
  }
}