swift UIAlertController与pickerView按钮操作熬夜

Question

我是swift的新手，我正试着UIAlertContoller PickerView 但我对巴克斯有问题， 这是一张照片

当我试图改变约束时，按钮保持不变 我在这里读了很多答案，但我没有找到任何solotuin

这是我的代码：

func distance(){
    let editRadiusAlert = UIAlertController(title: "Choose distance", message: "", preferredStyle: UIAlertControllerStyle.alert)
    let pickeViewFrame: CGRect = CGRect(x: 0, y: 0, width: 250, height: 300)
    let pickerViewRadius: UIPickerView = UIPickerView(frame: pickeViewFrame)
    pickerViewRadius.delegate = self
    pickerViewRadius.dataSource = self
    editRadiusAlert.view.addSubview(pickerViewRadius)
    editRadiusAlert.addAction(UIAlertAction(title: "Done", style: UIAlertActionStyle.default,handler:nil))
    editRadiusAlert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil))
    editRadiusAlert.view.addConstraint(NSLayoutConstraint(item: editRadiusAlert.view, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: self.view.frame.height * 0.5))
    self.present(editRadiusAlert, animated: true, completion: nil)
} 

Answer 1

不要将pickerView添加为子视图，而是尝试设置contentViewController这样的UIAlertController。

let vc = UIViewController()
vc.preferredContentSize = CGSize(width: 250,height: 300)
let pickerView = UIPickerView(frame: CGRect(x: 0, y: 0, width: 250, height: 300))
pickerView.delegate = self
pickerView.dataSource = self
vc.view.addSubview(pickerView)
let editRadiusAlert = UIAlertController(title: "Choose distance", message: "", preferredStyle: UIAlertControllerStyle.alert)
editRadiusAlert.setValue(vc, forKey: "contentViewController")
editRadiusAlert.addAction(UIAlertAction(title: "Done", style: .default, handler: nil))
editRadiusAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(editRadiusAlert, animated: true)

看起来如下。