From: AceVest Date: Sun, 19 Jun 2016 15:44:43 +0000 (+0800) Subject: closure X-Git-Url: http://zhaoyanbai.com/repos/man.dnssec-settime.html?a=commitdiff_plain;h=cabdb73e01b26d8bd49e88f0bd4bfec2f6f022fb;p=acecode.git closure --- diff --git a/learn/AcePlay/AcePlay.playground/Pages/Closure.xcplaygroundpage/Contents.swift b/learn/AcePlay/AcePlay.playground/Pages/Closure.xcplaygroundpage/Contents.swift index 66a43a8..cd5b70d 100644 --- a/learn/AcePlay/AcePlay.playground/Pages/Closure.xcplaygroundpage/Contents.swift +++ b/learn/AcePlay/AcePlay.playground/Pages/Closure.xcplaygroundpage/Contents.swift @@ -24,7 +24,7 @@ import UIKit */ -let company = ["Tencent", "Apple", "Facebook", "Google", "Twitter", "Amazon"] +var company = ["Tencent", "Apple", "Facebook", "Google", "Twitter", "Amazon"] var sortedCompany: [String] = [] printLine("Sort") @@ -120,11 +120,80 @@ func makeIncrementer(step:Int) -> () -> Int { return inc } -var closureFuncA = makeIncrementer(1) +// 闭包是引用类型 +let closureFuncA = makeIncrementer(1) print("ClosureFuncA:", closureFuncA()) print("ClosureFuncA:", closureFuncA()) -var closureFuncB = closureFuncA +let closureFuncB = closureFuncA print("ClosureFunnB:", closureFuncB()) -var closureFuncC = makeIncrementer(1) +let closureFuncC = makeIncrementer(1) print("ClosureFuncC:", closureFuncC()) + +// 逃逸&非逃逸闭包 +printLine("Noescaping & Escaping Closesure") +func noescapingClosure(@noescape closure: () -> Void) { + closure() +} + +var closureHandler: Array<() -> Void> = [] +func escapingClosure(closure: () -> Void) { // 此时参数前加@noescape会报错 + closureHandler.append(closure) +} + + +class ClosureClass { + var x = 10 + func doSomethingAboutEscape() { + noescapingClosure() { x = 200 } // 将参数标记为@noescape能在闭包中隐式地引用self + escapingClosure() { self.x = 100 } + } +} + +var closureInstance = ClosureClass() +closureInstance.doSomethingAboutEscape() +print(closureInstance.x) +closureHandler[0]() +print(closureInstance.x) + + +printLine("AutoClosure") +print("Now Company Items:", company) +print("Company Item Count:", company.count) +// autoClosureHanlerA的type是 () -> String 不是 String +let autoClosureHandlerA = { company.removeAtIndex(0) } // an autoclosure lets you delay evaluation +print("Company Item Count:", company.count) +print("No Remove \(autoClosureHandlerA())") +print("Company Item Count:", company.count) + + +// autoclosure parameter +printLine("AutoClosure Parameter") +func autoClosureFuncParameterA(closure: () -> String) { + print("AutoClosureFuncParameterA \(closure())!") +} +autoClosureFuncParameterA({ company.removeAtIndex(0) }) + +func autoClosureFuncParameterB(@autoclosure closure: () -> String) { + print("AutoClosureFuncParameterB \(closure())!") +} +autoClosureFuncParameterB(company.removeAtIndex(0)) + +// @autoclosure 暗含了 noescape 特性 +var autoClosureHanlder: [() -> String] = [] +func autoClosureFuncParameterC(@autoclosure closure: () -> String) { + //因为参数被@autoclosure修饰了,而@autoclosure暗含@noescape特性,因此以下语句会报错 + //autoClosureHanlder.append(closure) +} + +// 如果用了@autoclosure又要用escape特性,则用@autoclosure(escaping)修饰参数 +func autoClosureFuncParameterD(@autoclosure(escaping) closure: () ->String) { + print("Called autoClosureFuncParameterD") + autoClosureHanlder.append(closure) +} +autoClosureFuncParameterD(company.removeAtIndex(0)) +autoClosureFuncParameterD(company.removeAtIndex(0)) + +for handler in autoClosureHanlder { + print("autoClosure Handling \(handler())!") +} 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 5f08ca2..1bafc59 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