我尝试使用setter和getter函数将子视图(inputPopUp.swift)中的变量传递给父视图。这是我孩子视图中的代码:
var char: String!
var buttonPressed = String()
@IBAction func addButtonPressed(sender: AnyObject) {
buttonPressed = "addButton"
setChar("+")
getChar()
self.removeAnimate()
}
@IBAction func minusButtonPressed(sender: AnyObject) {
buttonPressed = "minusButton"
setChar("-")
self.removeAnimate()
}
@IBAction func divideButtonPressed(sender: AnyObject) {
buttonPressed = "divideButton"
setChar("/")
self.removeAnimate()
}
@IBAction func multiplyButtonPressed(sender: AnyObject) {
buttonPressed = "multiplyButton"
setChar("*")
self.removeAnimate()
}
//setter method
func setChar(var thisChar: String){
char = thisChar
}
//getter method
func getChar()-> String{
if (buttonPressed == "addButton"){
char = "+"
}
if (buttonPressed == "minusButton"){
char = "-"
}
if (buttonPressed == "divideButton"){
char = "/"
}
if (buttonPressed == "multiplyButton"){
char = "*"
}
return char
}
我正在尝试访问' char'我的父视图中的变量是这样的,但它返回nil - 大概是因为我正在调用函数的新实例。
@IBAction func runButtonPressed(sender: AnyObject) {
inputPopUp().getChar()
}
我还希望根据子视图中的按钮单击更新父视图中的标签。我正在尝试实施键值观察。这是我到目前为止所得到的。
class ObserveChar: NSObject {
dynamic var char = String()
func updateChar(){
char = String()
}
}
private var myContext = 0
class Observer: NSObject {
var objectToObserve = ObserveChar()
override init(){
super.init()
objectToObserve.addObserver(self, forKeyPath: "char", options: .New, context: &myContext)
}
override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
if context == &myContext {
println("Char updated: \(change[NSKeyValueChangeNewKey])")
} else {
super.observeValueForKeyPath(keyPath, ofObject: object, change: change, context: context)
}
}
deinit {
objectToObserve.removeObserver(self, forKeyPath: "char", context: &myContext)
}
}
答案 0 :(得分:1)
您的项目似乎与计算器有关。你不应该使用
ParentView().tapLabel.text = getChar()
因为,您已多次创建parentView,您应将parentView设置为其弱属性
您还可以使用KVO观察子视图的char变量;或者您也可以使用NSNotification更新父视图的tapLabel;或者您也可以使用委托。 代表喜欢以下
protocol UpdateTapLabel {
func didTapSomeOperateAction(operateInfo : String)
}
class ParentClass : NSObject, UpdateTapLabel {
var tapLabel : UILabel!
var childView : ChildView!
func didTapSomeOperateAction(operateInfo: String) {
self.tapLabel.text = operateInfo
}
//you should initialize the child view like this
/*
childView = ChildView()
childView.delegate = self
*/
}
class ChildView: NSObject {
var char: String!
var delegate : UpdateTapLabel
//getter method
func getChar() {
if (buttonPressed == "addButton"){
char = "+"
}
if (buttonPressed == "minusButton"){
char = "-"
}
if (buttonPressed == "divideButton"){
char = "/"
}
if (buttonPressed == "multiplyButton"){
char = "*"
}
self.delegate.didTapSomeOperateAction(char)
}
}
KVO喜欢以下
//you should add observer like this
//self.addObserver(self, forKeyPath: "childView.char", options: NSKeyValueObservingOptions.New, context: nil)
//also you should remove it in deinit, otherwise you will get crash when release parentView
deinit {
self.removeObserver(self, forKeyPath: "childView.char")
}
//you can handle the kvo here
override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
if keyPath == "childView.char" {
self.tapLabel.text = change[NSKeyValueChangeNewKey]
}
}
答案 1 :(得分:0)
好的,也许您可以将子视图设置为父视图的属性,也许就像这样
var inputPopView : inputPopUp /**<initialize it somewhere */
然后你可以像这样使用它
@IBAction func runButtonPressed(sender: AnyObject) {
self.inputPopView.getChar()
}