DispatchQueue.main.async {
          self.collectionView?.reloadData() // Depends if you were populating a collection view or table view
    }


OperationQueue.main.addOperation {
    self.lblGenre.text = self.movGenre
}

//使用操作队列如果你需要填充对象(标签，imageview, textview)在你的视图控制器

 DispatchQueue.main.async {
          self.collectionView?.reloadData() // Depends if you were populating a collection view or table view
    }


OperationQueue.main.addOperation {
    self.lblGenre.text = self.movGenre
}

//使用操作队列如果你需要填充对象(标签，imageview, textview)在你的视图控制器

   let concurrentQueue = dispatch_queue_create("com.swift3.imageQueue", DISPATCH_QUEUE_CONCURRENT) //Swift 2 version

   let concurrentQueue = DispatchQueue(label:"com.swift3.imageQueue", attributes: .concurrent) //Swift 3 version

我在Xcode 8, Swift 3中重做了你的代码，这些变化与你的Swift 2版本形成对比。

现在很简单:

let serialQueue = DispatchQueue(label: "my serial queue")

默认值是serial，要获得concurrent，可以使用可选属性参数.concurrent

斯威夫特3

你想在swift代码中调用一些闭包然后你想在storyboard中改变任何类型的改变属于视图，你的应用程序会崩溃

但是你要使用分派方法，你的应用程序不会崩溃

异步方法

DispatchQueue.main.async 
{
 //Write code here                                   

}

同步方法

DispatchQueue.main.sync 
{
     //Write code here                                  

}

在XCode 8编译，Swift 3 https://github.com/rpthomas/Jedisware

 @IBAction func tap(_ sender: AnyObject) {

    let thisEmail = "emailaddress.com"
    let thisPassword = "myPassword" 

    DispatchQueue.global(qos: .background).async {

        // Validate user input

        let result = self.validate(thisEmail, password: thisPassword)

        // Go back to the main thread to update the UI
        DispatchQueue.main.async {
            if !result
            {
                self.displayFailureAlert()
            }

        }
    }

}