A Superclass :
class MySuperView : UIView{
var aProperty ;
}
A subclass inheritance the super class :
class Subclass : MySuperClass{
// I want to override the aProperty's setter/getter method
}
I want to override the superclass's property's setter/getter method ,
how to override this method in Swift ? Please help me , thanks .
What do you want to do with your custom setter? If you want the class to do something before/after the value is set, you can use 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
Console Output:
WillSet aVar to 5 from 0
didSet aVar to 5 from 0
If, however, you want to completely change how the setter interacts with the superclass:
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
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