swift小技巧之获取keywindow

• 获取keywindow方法

  let keyWindow:UIWindow = {
      var window:UIWindow = UIApplication.shared.keyWindow!
      if #available(iOS 13.0, *) {
          window = UIApplication.shared.windows.filter({ $0.isKeyWindow }).last!
      }
      return window
  }()

• ios13之后获取
  

  let window = UIApplication.shared.windows.filter({ $0.isKeyWindow }).last

  或者
  

  let window = UIApplication.shared.connectedScenes
          .filter({ $0.activationState == .foregroundActive })
          .map({ $0 as? UIWindowScene })
          .compactMap({ $0 })
          .last?.windows
          .filter({ $0.isKeyWindow })
          .last