Swift-NSTimer & setNeedDisplay

Question

    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(setNeedsDisplay) userInfo:self repeats:YES];

我想知道如何用 swift 编写上面的代码。

Answer 1

计时器计划事件NSTimer's示例用法 -

// create a timer instance 
let timer = NSTimer(timeInterval: 1.0, target: self, selector: "timerEventTriggered:", userInfo: nil, repeats: true)
// adding timer to current run loop
NSRunLoop.currentRunLoop().addTimer(timer, forMode: NSRunLoopCommonModes)
// implement the event which is triggered by scheduled timer
func timerEventTriggered(timer:NSTimer!) {
    ...
}

注意：这只是示例用法，您可以根据上下文更改变量和方法名称。

Answer 2

var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("yourFunction"), userInfo: nil, repeats: true)

func yourFunction() {
    // Do something
 }

/////other way.......
 dispatch_after(timer, dispatch_get_main_queue()) { () -> Void in
     //do same like in yourFunction()
   }
 }

Answer 3

代码可以写成

斯威夫特 2

var timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("setNeedsDisplay"), userInfo: self, repeats: true)
func setNeedsDisplay() {
}

斯威夫特 3， 4， 5

var timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(self.setNeedsDisplay), userInfo: self, repeats: true)
@objc func setNeedsDisplay() {
}

Answer 4

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