Swift如何获得UIAlertController标题的高度

目前我正在使用UIAlertController在迅速。 我正在尝试向我的警报控制器添加一个活动指示器。 我发现了以下解决scheme，但是当标题大于一行时，微调器和标题重叠。 为此我想，我需要知道标题标签的高度。

let spinner = UIActivityIndicatorView(activityIndicatorStyle: .gray) spinner.center = CGPoint(x: 130.5, y: 65.5) spinner.startAnimating() alert.view.addSubview(spinner) 

有人请帮助我一个适当的解决scheme。

Answer 1

据我所知，不能访问标题高度。 在警报视图中添加自定义UIView很容易，然后在自定义视图上添加标题标签，微调框，消息标签。

  let alert = UIAlertController(title: " ", message: " ", preferredStyle: UIAlertControllerStyle.alert) let customViewWidth: CGFloat = 270 let viewRect = CGRect(x: 0, y: 0, width: customViewWidth, height: 150) let customView = UIView(frame: viewRect) customView.backgroundColor = UIColor.white customView.layer.cornerRadius = 20.0 customView.clipsToBounds = true var spinnerTopPadding: CGFloat = 17.0 if(!title.isEmpty) { let titleRect = CGRect(x: 13.0, y: 17.0, width: customViewWidth - 26, height: 100) let titleLabel = UILabel(frame: titleRect) titleLabel.textAlignment = .center titleLabel.numberOfLines = 0 titleLabel.font = titleLabel.font(withSize: 17.0) titleLabel.lineBreakMode = .byWordWrapping titleLabel.text = title titleLabel.sizeToFit() titleLabel.center = CGPoint(x: customViewWidth / 2, y: titleLabel.frame.size.height / 2 + 17.0) customView.addSubview(titleLabel) spinnerTopPadding = titleLabel.frame.size.height + 27 } let spinner = UIActivityIndicatorView(activityIndicatorStyle: .gray) spinner.center = CGPoint(x: customViewWidth / 2, y: spinnerTopPadding + spinner.frame.size.height / 2) spinner.startAnimating() customView.addSubview(spinner) var messageText = message.replacingOccurrences(of: "\n\n", with: "") messageText = message.replacingOccurrences(of: "\n", with: "") var spinnerBottomPadding: CGFloat = 17.0 if (!message.isEmpty) { let messageRect = CGRect(x: 13.0, y: spinnerTopPadding + spinner.frame.size.height + 10.0, width: customViewWidth - 26, height: 100) let messageLabel = UILabel(frame: messageRect) messageLabel.textAlignment = .center messageLabel.numberOfLines = 0 messageLabel.font = messageLabel.font(withSize: 14.0) messageLabel.lineBreakMode = .byWordWrapping messageLabel.text = messageText messageLabel.sizeToFit() messageLabel.center = CGPoint(x: customViewWidth / 2, y: spinnerTopPadding + spinner.frame.size.height + messageLabel.frame.size.height / 2 + 10) customView.addSubview(messageLabel) spinnerBottomPadding = messageLabel.frame.size.height + 27 } customView.frame.size.height = spinnerTopPadding + spinner.frame.size.height + spinnerBottomPadding alert.view.addSubview(customView) let alertControllerHeight = NSLayoutConstraint(item: alert.view, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: customView.frame.size.height) let alertControllerWidth = NSLayoutConstraint(item: alert.view, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: customViewWidth) alert.view.addConstraint(alertControllerHeight) alert.view.addConstraint(alertControllerWidth) let alertContainer = alert.view.subviews.first!.subviews.first! for container in alertContainer.subviews { container.backgroundColor = UIColor.white container.layer.cornerRadius = 20.0 } self.present(alert, animated: true, completion: nil)