下面是Swift 3在延迟后排队工作的方法。

DispatchQueue.main.asyncAfter(
  DispatchTime.now() + DispatchTimeInterval.seconds(2)) {
    // do work
}

这里是我的2美分= 5个方法;)

我喜欢封装这些细节，让AppCode告诉我如何完成我的句子。

void dispatch_after_delay(float delayInSeconds, dispatch_queue_t queue, dispatch_block_t block) {
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
    dispatch_after(popTime, queue, block);
}

void dispatch_after_delay_on_main_queue(float delayInSeconds, dispatch_block_t block) {
    dispatch_queue_t queue = dispatch_get_main_queue();
    dispatch_after_delay(delayInSeconds, queue, block);
}

void dispatch_async_on_high_priority_queue(dispatch_block_t block) {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), block);
}

void dispatch_async_on_background_queue(dispatch_block_t block) {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), block);
}

void dispatch_async_on_main_queue(dispatch_block_t block) {
    dispatch_async(dispatch_get_main_queue(), block);
}

下面是Swift 3在延迟后排队工作的方法。

DispatchQueue.main.asyncAfter(
  DispatchTime.now() + DispatchTimeInterval.seconds(2)) {
    // do work
}

在BlocksKit框架中有一个很好的例子。

BlocksKit

(和班级)

BBlocksKit.m

Swift 3和Xcode 8.3.2

这段代码将帮助你，我也添加了一个解释

// Create custom class, this will make your life easier
class CustomDelay {

    static let cd = CustomDelay()

    // This is your custom delay function
    func runAfterDelay(_ delay:Double, closure:@escaping ()->()) {
        let when = DispatchTime.now() + delay
        DispatchQueue.main.asyncAfter(deadline: when, execute: closure)
    }
}


// here how to use it (Example 1)
class YourViewController: UIViewController {

    // example delay time 2 second
    let delayTime = 2.0

    override func viewDidLoad() {
        super.viewDidLoad()

        CustomDelay.cd.runAfterDelay(delayTime) {
            // This func will run after 2 second
            // Update your UI here, u don't need to worry to bring this to the main thread because your CustomDelay already make this to main thread automatically :)
            self.runFunc()
        }
    }

    // example function 1
    func runFunc() {
        // do your method 1 here
    }
}

// here how to use it (Example 2)
class YourSecondViewController: UIViewController {

    // let say you want to user run function shoot after 3 second they tap a button

    // Create a button (This is programatically, you can create with storyboard too)
    let shootButton: UIButton = {
        let button = UIButton(type: .system)
        button.frame = CGRect(x: 15, y: 15, width: 40, height: 40) // Customize where do you want to put your button inside your ui
        button.setTitle("Shoot", for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false
        return button
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        // create an action selector when user tap shoot button
        shootButton.addTarget(self, action: #selector(shoot), for: .touchUpInside)   
    }

    // example shoot function
    func shoot() {
        // example delay time 3 second then shoot
        let delayTime = 3.0

        // delay a shoot after 3 second
        CustomDelay.cd.runAfterDelay(delayTime) {
            // your shoot method here
            // Update your UI here, u don't need to worry to bring this to the main thread because your CustomDelay already make this to main thread automatically :)
        }
    }   
}

以下是在Swift中延迟后触发阻塞的方法:

runThisAfterDelay(seconds: 2) { () -> () in
    print("Prints this 2 seconds later in main queue")
}

/// EZSwiftExtensions
func runThisAfterDelay(seconds seconds: Double, after: () -> ()) {
    let time = dispatch_time(DISPATCH_TIME_NOW, Int64(seconds * Double(NSEC_PER_SEC)))
    dispatch_after(time, dispatch_get_main_queue(), after)
}

它包括作为一个标准函数在我的回购。