超类：
@H_403_1@class MySuperView : UIView{
var aProperty ;
}
一个子类继承超类：
@H_403_1@class Subclass : MySuperClass{ // I want to override the aProperty's setter/getter method }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：
@H_403_1@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
Console Output:
WillSet aVar to 5 from 0
didSet aVar to 5 from 0
但是,如果您想完全改变setter与超类的交互方式：
@H_403_1@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)Console output:
0
Would have set aVar to 5 from 0
0
