前端之家收集整理的这篇文章主要介绍了
swift delegate，
前端之家小编觉得挺不错的，现在分享给大家，也给大家做个参考。
protocol ModelDelegate {
func willValueChanged(curValue: Int,newValue: Int)
func didValueChanged(curValue: Int,oldValue: Int)
}
class Model {
var delegate: ModelDelegate?
var count: Int = 0 {
willSet {
delegate?.willValueChanged(count,newValue: newValue)
}
didSet {
delegate?.didValueChanged(count,oldValue: oldValue)
}
}
}
class View: ModelDelegate {
func willValueChanged(curValue: Int,newValue: Int) {
print("will,cur:\(curValue),new:\(newValue)")
}
func didValueChanged(curValue: Int,oldValue: Int) {
print("did,old:\(oldValue)")
}
}
let model = Model()
let view = View()
model.delegate = view
model.count = 100
model.count = 200
