仿了一个博主的计时器，他用oc写的，我用swift翻译了一遍。在这里给这个博主抱拳了！

这里是展示demo：

录屏.gif

import UIKit
let DEFAULT_STARTTEXT  = "获取验证码"
let DEFAULT_ENDTEXT    = "重新获取"

class ZCodeButton: UIButton {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setCodeButton()
    }

    required init(coder aDecoder: NSCoder) { 
        super.init(coder: aDecoder)!
        setCodeButton()
        // fatalError("init(coder:) has not been implemented")
    }
    
  
    var startText:String?      = DEFAULT_STARTTEXT    //开始提示
    var endText:String?        = DEFAULT_ENDTEXT     //结束提示
    //默认时间
    var time:NSTimeInterval    = 60        //默认60秒
    
    
    //UI属性
    var textFont:CGFloat       = 13        //字体大小
    var cornerRadius:CGFloat   = 5         //弧度
    var boardWitdh:CGFloat     = 0         //外边框宽度
    var boardColor:UIColor     = UIColor.darkGrayColor()   //边框颜色
    var startBackColor         = UIColor.lightGrayColor()  //起始颜色
    var endBackColor           = UIColor.darkGrayColor()   //结束颜色
    var startTextColor:UIColor = UIColor.whiteColor()      //起始字体颜色
    var endTextColor:UIColor   =  UIColor.whiteColor()     //结束字体颜色
    
    //私有属性
    var indexTime:NSTimeInterval  =   60
    
    //初始化设置CodeButton
    func setCodeButton(){
        self.layer.borderColor   = self.boardColor.CGColor
        self.layer.borderWidth   = self.boardWitdh
        self.layer.masksToBounds =  true
        self.layer.cornerRadius  = self.cornerRadius
        self.setTitle(self.startText, forState: UIControlState.Normal)
        self.setTitleColor(startTextColor, forState: UIControlState.Normal)
        self.titleLabel?.font    = UIFont.systemFontOfSize(13)
        self.backgroundColor     = BUTTON_COLOR
        self.indexTime           = time
        
    }
    
    func start(){
        self.titleLabel!.transform = CGAffineTransformMakeScale(0.9, 0.9);
        self.titleLabel!.alpha     = 1
        self.setTitleColor(startBackColor, forState: UIControlState.Normal)
        self.setTitleColor(endTextColor, forState: UIControlState.Disabled)
        self.backgroundColor = startBackColor
        self.enabled = false
        if indexTime > 0{
 
            weak var weakSelf = self
            self.setTitle("\(Int(weakSelf!.indexTime))秒", forState: UIControlState.Normal)
            self.setTitle("\(Int(weakSelf!.indexTime))秒", forState: UIControlState.Disabled)
            
            UIView.animateWithDuration(1, animations: { () -> Void in
               self.titleLabel!.transform = CGAffineTransformMakeScale(1, 1)
               self.titleLabel!.alpha     = 0
            }, completion: { (completion) -> Void in
                if weakSelf != nil{
                --weakSelf!.indexTime
                  weakSelf!.start()
                }else{
                weakSelf?.removeFromSuperview()
                }
            })
        }else{
            indexTime = time
            self.enabled = true
            self.setTitle(self.endText, forState: UIControlState.Normal)
            self.setTitleColor(endTextColor, forState: UIControlState.Normal)
            self.backgroundColor = BUTTON_COLOR
        }
        
    }

    }

用的时候直接调用start()方法就可以了。
有什么不懂的可以留言给我。也谢谢各位大神指导