timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(createEnemy), userInfo: nil, repeats: true)

通过createEnemy这个名字创造乐趣

fund createEnemy ()
{
do anything ////
}

这是可行的:

override func viewDidLoad() {
    super.viewDidLoad()
    // Swift block syntax (iOS 10+)
    let timer = Timer(timeInterval: 0.4, repeats: true) { _ in print("Done!") }
    // Swift >=3 selector syntax
    let timer = Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(self.update), userInfo: nil, repeats: true)
    // Swift 2.2 selector syntax
    let timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: #selector(MyClass.update), userInfo: nil, repeats: true)
    // Swift <2.2 selector syntax
    let timer = NSTimer.scheduledTimerWithTimeInterval(0.4, target: self, selector: "update", userInfo: nil, repeats: true)
}

// must be internal or public. 
@objc func update() {
    // Something cool
}

对于Swift 4，你想要获取选择器的方法必须暴露在Objective-C中，因此@objc属性必须添加到方法声明中。

检查:

斯威夫特2

var timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: Selector("update"), userInfo: nil, repeats: true)

斯威夫特，3,4,5

var timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(self.update), userInfo: nil, repeats: true)

在iOS 10中，还有一个新的基于块的定时器工厂方法，它比使用选择器更干净:

    _ = Timer.scheduledTimer(withTimeInterval: 5, repeats: false) { timer in
        label.isHidden = true
    }

swift 3和Xcode 8.2 (有块很好，但如果你编译为iOS9和想要userInfo):

...

        self.timer = Timer(fireAt: fire,
                           interval: deltaT,
                           target: self,
                           selector: #selector(timerCallBack(timer:)),
                           userInfo: ["custom":"data"],
                           repeats: true)

        RunLoop.main.add(self.timer!, forMode: RunLoopMode.commonModes)
        self.timer!.fire()
}

func timerCallBack(timer: Timer!){
        let info = timer.userInfo
        print(info)
    }

斯威夫特5

我个人更喜欢带块闭包的定时器:

    Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { (_) in
       // TODO: - whatever you want
    }