我尝试在类的扩展上声明IBOutlet属性.但它给出错误
‘var’ declaration without getter/setter method not allowed here
class ExampleView : UIView { } extension ExampleView { @IBOutlet var btn1,btn2 : UIButton // here I got error. }
请任何人建议我正确的做法吗?
解决方法
来自扩展 – > Swift编程语言中的计算属性
NOTE
Extensions can add new computed properties,but they cannot add stored
properties,or add property observers to existing properties.
另外响应twlkyao的评论:这是我的一个Double的absoluteValue属性的实现
extension Double { var absoluteValue: Double { if self >= 0 { return self } else { return -self } } } // Simple test -> BOTH println() should get called. var a = -10.0 if (a < 0) { println("Smaller than Zero") } if (a.absoluteValue > 5) { println("Absolute is > 5") }