From: AceVest <zhaoyanbai@126.com>
Date: Mon, 13 Mar 2017 15:54:04 +0000 (+0800)
Subject: ...
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=8cce995887e8552fd42cb1e2cfb5dcf092716bff;p=acecode.git

...
---

diff --git a/learn/AcePlay/AcePlay.playground/Pages/Methods.xcplaygroundpage/Contents.swift b/learn/AcePlay/AcePlay.playground/Pages/Methods.xcplaygroundpage/Contents.swift
new file mode 100644
index 0000000..745b406
--- /dev/null
+++ b/learn/AcePlay/AcePlay.playground/Pages/Methods.xcplaygroundpage/Contents.swift
@@ -0,0 +1,179 @@
+//: [Previous](@previous)
+
+import Foundation
+
+var str = "Hello, playground"
+
+//: [Next](@next)
+
+class Counter {
+    var count = 0
+    
+    func increment() {
+        count += 1
+    }
+    
+    func increment(by amount: Int) {
+        count += amount
+    }
+    
+    func reset() {
+        count = 0
+    }
+}
+
+var counter = Counter()
+
+counter.increment()
+print(counter.count)
+counter.increment(by: 100)
+print(counter.count)
+counter.reset()
+print(counter.count)
+
+struct Point {
+    var x = 0.0, y = 0.0
+    // 结构体和枚举是值类型。默认情况下，值类型的属性不能在它的实例方法中被修改，如果要修改将关键字mutating 放到方法的func关键字之前
+    mutating func move(x deltaX: Double, y deltaY: Double) {
+        self.x += deltaX
+        self.y += deltaY
+    }
+    
+    // 可变方法能够赋给隐含属性self一个全新的实例
+    mutating func moveTo(x deltaX: Double, y deltaY: Double) {
+        self = Point(x: deltaX, y: deltaY)
+    }
+    var description: String {
+        get {
+            return "Point(\(x), \(y))"
+        }
+    }
+}
+
+
+var point = Point()
+print(point.description)
+point.move(x: 1, y: 7)
+print(point.description)
+point.move(x: 8, y: 4)
+print(point.description)
+point.moveTo(x: 9, y: 9)
+print(point.description)
+
+
+// 枚举的可变方法可以把self设置为同一枚举类型中不同的成员
+enum TriStateSwitch: String {
+    case Off
+    case Low
+    case High
+    
+    mutating func next() {
+        switch self {
+        case .Off:
+            self = .Low
+        case .Low:
+            self = .High
+        case .High:
+            self = .Off
+        }
+    }
+    
+    var description: String {
+        return "Current State: \(self.rawValue)"
+    }
+}
+
+var ovenLight = TriStateSwitch.High
+print(ovenLight.description)
+ovenLight.next()
+print(ovenLight.description)
+ovenLight.next()
+print(ovenLight.description)
+ovenLight.next()
+print(ovenLight.description)
+
+// 类型方法
+class SomeClass {
+    // static & class 加在func前都是定义类型方法的关键字
+    // 不同的是static的不能被子类重写该方法
+    // 而class则可以
+    static func descV1() -> String {
+        return "BaseDescV1"
+    }
+    class func descV2() -> String {
+        return "BaseDescV2"
+    }
+}
+
+class SomeDerivedClass: SomeClass {
+    /*
+    取消注释会编译错误
+    override static func descV1() -> String {
+        return "BaseDescV1"
+    }
+    */
+    override class func descV2() -> String {
+        return "DerivedDescV2"
+    }
+}
+
+print(SomeClass.descV1())
+print(SomeClass.descV2())
+print(SomeDerivedClass.descV1())
+print(SomeDerivedClass.descV2())
+
+
+class LevelTracker {
+    static var highestUnlockedLevel = 1
+    var currentLevel = 1
+    
+    static func unlock(_ level: Int) {
+        if level > highestUnlockedLevel {
+            highestUnlockedLevel = level
+        }
+    }
+    
+    static func isUnlocked(_ level: Int) -> Bool {
+        return level <= highestUnlockedLevel
+    }
+    
+    @discardableResult  // 可以忽略返回值，不会产生警告
+    func advance(to level: Int) -> Bool {
+        if LevelTracker.isUnlocked(level) {
+            currentLevel = level
+            return true
+        } else {
+            return false
+        }
+    }
+}
+
+class Player {
+    var tracker = LevelTracker()
+    let playerName: String
+    
+    init(name: String) {
+        self.playerName = name
+    }
+    
+    func complete(level: Int) {
+        LevelTracker.unlock(level)
+        tracker.advance(to: level)
+    }
+}
+
+
+var player = Player(name: "Ace")
+player.complete(level: 1)
+player.complete(level: 2)
+if player.tracker.advance(to: 3) {
+    print("player is now on level 3")
+} else {
+    print("level 3 has not yet been unlocked")
+}
+player.complete(level: 3)
+if player.tracker.advance(to: 3) {
+    print("- player is now on level 3")
+} else {
+    print("- level 3 has not yet been unlocked")
+}
diff --git a/learn/AcePlay/AcePlay.playground/Pages/Properties.xcplaygroundpage/Contents.swift b/learn/AcePlay/AcePlay.playground/Pages/Properties.xcplaygroundpage/Contents.swift
index d343e4d..be3145e 100644
--- a/learn/AcePlay/AcePlay.playground/Pages/Properties.xcplaygroundpage/Contents.swift
+++ b/learn/AcePlay/AcePlay.playground/Pages/Properties.xcplaygroundpage/Contents.swift
@@ -51,7 +51,6 @@ print("the DataImporter instance for the importer property has not yet been crea
 dataManager.importer
 
 
-
 printLine("Computed Properties")
 
 struct Point {
@@ -67,6 +66,7 @@ struct Rect {
     var origin = Point()
     var size   = Size()
     
+    // 必须使用 var 关键字定义计算属性，包括只读计算属性，因为它们的值不是固定的
     var center: Point {
         get {
             var p = Point()
@@ -81,7 +81,7 @@ struct Rect {
         }
         
         /*
-         //set 有更简洁的写法，set重命名参数的话默认参数名为newValue
+        //set 有更简洁的写法，set重命名参数的话默认参数名为newValue
          
         set {
             origin.x = newValue.x - size.width/2
@@ -119,3 +119,83 @@ class Cuboid {
 
 let fourByFiveByTwo = Cuboid(width:4.0, height:5.0, depth:2.0)
 print(fourByFiveByTwo.volume)
+
+
+// 属性观察器
+class StepCounter
+{
+    var totalSteps: Int = 0 {
+        // 默认的分别是newValue & oldValue
+        willSet(newValue) {
+            print("About to set totalSteps to \(newValue)")
+        }
+        
+        didSet {
+            if totalSteps > oldValue {
+                print("Added \(totalSteps-oldValue) steps")
+            }
+        }
+    }
+    
+    var serialNumber: String = "0000-00000-0000000-000" {
+        // 不想用newValue & oldValue 可以命名为别的方法
+        willSet(newSerialNumber) {
+            print("New serial number \(newSerialNumber)")
+        }
+        
+        didSet(oldSerialNumber) {
+            print("Old serial number \(oldSerialNumber)")
+        }
+    }
+}
+
+
+let stepCounter = StepCounter()
+
+stepCounter.totalSteps = 100
+stepCounter.totalSteps = 300
+stepCounter.totalSteps = 657
+stepCounter.totalSteps = 257
+stepCounter.serialNumber = "0010-23873-83F123A-ECA"
+stepCounter.serialNumber = "10A0-8376C-247232E-EST"
+
+
+// 类型属性
+struct SomeStructure {
+    static var storedType = "Structure"
+    static var computedType: Int {
+        return 1;
+    }
+}
+
+enum SomeEnumeration {
+    static var v: String = "ComputedEnumeration"
+    static var storedType = "Enumeration"
+    static var computedType: String {
+        get {
+            return "get" + v
+        }
+        
+        set(v) {
+            self.v = v
+        }
+    }
+}
+
+class SomeClass {
+    static var storedType = "Class"
+    static var computedType: String {
+        return "ComputedClass"
+    }
+}
+
+print(SomeStructure.storedType)
+print(SomeEnumeration.storedType)
+print(SomeClass.storedType)
+
+print(SomeStructure.computedType)
+print(SomeEnumeration.computedType)
+SomeEnumeration.computedType = "ComputedEnumerationV2"
+print(SomeEnumeration.computedType)
+print(SomeClass.computedType)
+
diff --git a/learn/AcePlay/AcePlay.playground/contents.xcplayground b/learn/AcePlay/AcePlay.playground/contents.xcplayground
index a6a057a..52e276f 100644
--- a/learn/AcePlay/AcePlay.playground/contents.xcplayground
+++ b/learn/AcePlay/AcePlay.playground/contents.xcplayground
@@ -9,5 +9,6 @@
         <page name='Properties'/>
         <page name='CollectionTypes'/>
         <page name='ControlFlow'/>
+        <page name='Methods'/>
     </pages>
 </playground>
\ No newline at end of file
diff --git a/learn/AcePlay/AcePlay.playground/playground.xcworkspace/xcuserdata/Ace.xcuserdatad/UserInterfaceState.xcuserstate b/learn/AcePlay/AcePlay.playground/playground.xcworkspace/xcuserdata/Ace.xcuserdatad/UserInterfaceState.xcuserstate
index 4a9ccd9..5d871e6 100644
Binary files a/learn/AcePlay/AcePlay.playground/playground.xcworkspace/xcuserdata/Ace.xcuserdatad/UserInterfaceState.xcuserstate and b/learn/AcePlay/AcePlay.playground/playground.xcworkspace/xcuserdata/Ace.xcuserdatad/UserInterfaceState.xcuserstate differ