今天是學(xué)習(xí)swift的第二天褂删，主要講的是OC代碼遷移到swift當(dāng)中
一.懶加載
格式:
lazy var變量名：變量類型= {
定義一個同樣類型的常量賦值后return出來
}()
lazy var array:[String] = {
let list = ["123","234","345"]
returnlist
}()
二.單例
單例兩種創(chuàng)建方式
第一種：static let 名字:類型 = {
let instance = 類型()
return instance
}()
static let shareSingleTon:SingleTon = {
let instance = SingleTon()
return instance
}()
第二種：static let instance = 類名()
class func shareSingTon()->返回值類型
{
return instance
}
static let instance = SingleTon()
class func shareSingTon()->SingleTon
{
return instance
}
三.代理
代理的步驟
如果協(xié)議里面有一些方法是選擇實現(xiàn)的宣羊，必須在標(biāo)識符protocol前面加上@objc温鸽，并且選擇實現(xiàn)的那些方法前面要加上optional修飾,必須實現(xiàn)的方法則一樣不用修飾符
?設(shè)置兩個協(xié)議
protocol womanDelegate{
func makeMoney()
}
@objc protocol womanOptionalDelegate{
// 可選擇實現(xiàn)的方法
optional func washCloses()
// 必須實現(xiàn)的方法
func introduceMySelf()
}
設(shè)置代理
var delegate:womanDelegate?
var optionaldelegate:womanOptionalDelegate?
引入代理
class ViewController: UIViewController,womanDelegate,womanOptionalDelegate {
}
實現(xiàn)代理方法
func makeMoney() {
print("viewcontroller make money")
}
func introduceMySelf() {
print("viewcontroller introller myself")
}
最后必須實現(xiàn)的方法如果沒有實現(xiàn)弛随，程序則會報錯
四.KVC
KVC調(diào)用流程：KVC(是一種通過字符串間接的訪問對象屬性的一種方式)
1疫稿，調(diào)用 setValuesForKeysWithDictionary
2铁坎，調(diào)用setvalue:forKey
-如果有找到對象的key值碳抄，則初始化并且賦值晾腔，沒有的話則到第3步
3舌稀，setvalue：forUndefinekey:
var name:String?
var age:Int = 0//基本數(shù)據(jù)類型在模型里面不能為可選類型，否則在KVC賦值的時候會找不到相應(yīng)的key值
var gender:String?
init(dict:[String:AnyObject]) {
super.init()
setValuesForKeysWithDictionary(dict)
}
override func setValue(value: AnyObject?, forKey key: String) {
super.setValue(value, forKey: key)
}
override func setValue(value: AnyObject?, forUndefinedKey key: String) {
}
五.用懶加載的方式創(chuàng)建UI控件灼擂，并且實現(xiàn)頁面的跳轉(zhuǎn)和傳值
lazy var btn:UIButton = {
let button = UIButton(frame: CGRectMake(70,70,50,50))
button.backgroundColor = UIColor.redColor()
// Selector("btnAction:") #selector(btnAction:)
button.addTarget(self, action: "btnAction:", forControlEvents: UIControlEvents.TouchUpInside)
return button
}()
lazy var label:UILabel = {
let temp = UILabel(frame: CGRectMake(70,150,90,30))
temp.backgroundColor = UIColor.cyanColor()
return temp
}()
func btnAction(btn:UIButton){
let secondVC = SecondViewController()
secondVC.closure = {
(str:String)->()
in
self.label.text = str
}
navigationController?.pushViewController(secondVC, animated: true)
}
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.whiteColor()
view.addSubview(btn)
view.addSubview(label)
}
var closure:((str:String)->())?
lazy var btn:UIButton = {
let button = UIButton(frame: CGRectMake(70,70,50,50))
button.backgroundColor = UIColor.blueColor()
button.addTarget(self, action: "btnAction:", forControlEvents: UIControlEvents.TouchUpInside)
return button
}()
lazy var textfield:UITextField = {
let tetx = UITextField(frame: CGRectMake(70,150,150,50))
tetx.backgroundColor = UIColor.redColor()
return tetx
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.cyanColor()
view.addSubview(btn)
view.addSubview(textfield)
}
func btnAction(btn:UIButton){
// 執(zhí)行閉包
closure!(str: textfield.text!)
navigationController?.popViewControllerAnimated(true)
}
