如何在Swift中更改UIAlertController中UITextField的高度？

Question

我在UIAlertController中添加了UITextField。我想改变文本字段的高度。我试过这种方式：

let alertController = UIAlertController(title: "Comments", message: "Write your comments here", preferredStyle: UIAlertControllerStyle.alert) 
alertController.addTextField { (textField : UITextField) -> Void in 
    var frame: CGRect = textField.frame 
    frame.size.height = 100 
    textField.frame = frame 
    textField.placeholder = "comment" 
    print(textField.frame.size.height) 
} 

let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel) { (result : UIAlertAction) -> Void in 
} 

let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default) { (result : UIAlertAction) -> Void in 
} 

alertController.addAction(cancelAction) 
alertController.addAction(okAction) 
self.present(alertController, animated: true, completion: nil) 

它不工作。

Answer 1

这适用于约束。

alertController.addTextField { textField in 
    let heightConstraint = NSLayoutConstraint(item: textField, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 100) 
    textField.addConstraint(heightConstraint) 
} 

Answer 2

@ the4kman给出了正确的答案，但你可以通过使用高度锚添加更容易限制：

textField.addConstraint(textField.heightAnchor.constraint(equalToConstant: 100))