swift NSOperation多线程无法输出结果

Question

import Foundation

//1.创建其他队列
let queue = NSOperationQueue()

//2.创建NSBlockOperation对象
let operation = NSBlockOperation { () -> Void in
    NSLog("%@", NSThread.currentThread())
}

//3.添加多个Block
for i in 0..<5 {
    operation.addExecutionBlock { () -> Void in
        NSLog("第%ld次 - %@", i, NSThread.currentThread())
    }
}

//4.队列添加任务
queue.addOperation(operation) 

为什么这段代码运行后什么结果都没有输出，原教程里面明明有输出结果的啊！是不是xCode里面需要设置一些地方才可以实现异步多线程？

Answer 1

http://www.tuicool.com/articles/MfAR7b