好的，使用评论中的信息 - 特别是这个(重点是我的):

Ok, with the information from the comments - specifically this (emphasis mine):

@Losiowaty 我明白你的意思，在我的StoryBoard 并连接它，但为什么我有 PickerView 即使 我没有在我的 StoryBoard 上放一个 UIPicerView

@Losiowaty I see what you mean, to create a UIPickerView on my StoryBoard and connect it, but why I have a PickerView even if I don't put a UIPicerView on my StoryBoard

选择器视图的 @IBOutlet 具有误导性.根据以上信息，问题似乎是您从未分配给 self.pickerView.在 viewDidLoad 你有这个代码:

The @IBOutlet for the picker view was misleading. With the above information, it seems that the issue is that you never assign to self.pickerView. In viewDidLoad you have this code :

let pickerView = UIPickerView(frame: CGRectMake(0, 200, view.frame.width, 100))
pickerView.showsSelectionIndicator = true
pickerView.delegate = self
pickerView.dataSource = self

只需在下面添加 self.pickerView = pickerView 就可以了.

Simply add self.pickerView = pickerView below this and everything should be fine.

请注意，当您以编程方式创建视图时，您不需要也不应该将它们注释为 @IBOutlets.它降低了代码对其他人的可读性，甚至可能在一段时间后对您来说也是如此.IBOutlet 代表 Interface Builder Outlet.

Note, that when you create views programatically you don't need and shouldn't annotate them as @IBOutlets. It makes the code less readable for someone else, and maybe even for you after some time. IBOutlet stands for Interface Builder Outlet.