超类：
class MySuperView : UIView{
var aProperty ;
}
@H_502_3@一个子类继承超类：
class Subclass : MySuperClass{
// I want to override the aProperty's setter/getter method
}
@H_502_3@我想覆盖超类的属性的setter / getter方法,
@H_502_3@如何在Swift中覆盖此方法？请帮助我,谢谢.
你想用自定义设置器做什么？如果您希望该类在设置值之前/之后执行某些操作,则可以使用willSet / didSet：
class TheSuperClass {
var aVar = 0
}
class SubClass: TheSuperClass {
override var aVar: Int {
willSet {
print("WillSet aVar to \(newValue) from \(aVar)")
}
didSet {
print("didSet aVar to \(aVar) from \(oldValue)")
}
}
}
let aSub = SubClass()
aSub.aVar = 5
@H_502_3@Console Output: @H_502_3@WillSet aVar to 5 from 0 @H_502_3@didSet aVar to 5 from 0@H_502_3@但是,如果您想完全改变setter与超类的交互方式：
class SecondSubClass: TheSuperClass {
override var aVar: Int {
get {
return super.aVar
}
set {
print("Would have set aVar to \(newValue) from \(aVar)")
}
}
}
let secondSub = SecondSubClass()
print(secondSub.aVar)
secondSub.aVar = 5
print(secondSub.aVar)
@H_502_3@Console output: @H_502_3@0 @H_502_3@Would have set aVar to 5 from 0 @H_502_3@0
