SWIFT 闭包的简单使用二

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
// Override point for customization after application launch.
self.window!.backgroundColor = UIColor.whiteColor()

self.window!.rootViewController = RootViewController()

self.window!.makeKeyAndVisible()
return true
}
}

import UIKit

class RootViewController: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()
//调用processData函数
processData { () -> Int in
print("回调")
return 20
}
}
/**
* 闭包返回整型数据
*/
func processData(printSomething:()->Int){
print("执行操作")
//执行闭包回调
let num = printSomething()
print("闭包返回值num:\(num)")
}

}