参见英文答案 >
UIControlState.Normal is Unavailable3个
@IBOutlet weak var catParentIdButton: UIButton!
解决方法
方法签名在Swift 3.0中更改
func setTitle(_ title: String?,for state: UIControlState) // Use this method to set the title for the button
例：
btn.setTitle(title: "Title",for: .normal)
注意btn控件的默认状态更改为.Normal到.normal.
// prevIoUs public static var Normal: UIControlState { get } // Swift 3.0 static var normal: UIControlState { get }
