class MySuperView : UIView{
var aProperty ;
}
一个子类继承超类：
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.
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：
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
