Swift - 通过叠加UILabel来实现混合的进度条

 

效果

 

源码

////  MixedColorProgressViewController.swift//  Swift-Animations////  Created by YouXianMing on 16/8/21.//  Copyright © 2016年 YouXianMing. All rights reserved.//import UIKitclass MixedColorProgressViewController: NormalTitleViewController {        private var upView    : UIView!    private var upLabel   : UILabel!    private var downView  : UIView!    private var downLabel : UILabel!    private var timer     : GCDTimer! = GCDTimer(inQueue: GCDQueue.mainQueue)        override func setup() {                super.setup()                downView                     = UIView(frame: CGRectMake(0, 0, 220, 17))        downView.center              = (contentView?.middlePoint)!        downView.layer.cornerRadius  = 2        downView.backgroundColor     = UIColor.whiteColor()        downView.layer.masksToBounds = true        contentView?.addSubview(downView)                downLabel                  = UILabel(frame: downView.bounds)        downLabel.font             = UIFont.HelveticaNeueThin(12.0)        downLabel.text             = "YouXianMing - iOS Programmer"        downLabel.textColor        = UIColor.redColor()        downLabel.textAlignment    = .Center        downView.layer.borderWidth = 0.5        downView.layer.borderColor = UIColor.redColor().CGColor        downView.addSubview(downLabel)                upView                     = UIView(frame: CGRectMake(0, 0, 220, 17))        upView.center              = (contentView?.middlePoint)!        upView.layer.cornerRadius  = 2        upView.backgroundColor     = UIColor.redColor()        upView.layer.masksToBounds = true        contentView?.addSubview(upView)                upLabel               = UILabel(frame: upView.bounds)        upLabel.font          = UIFont.HelveticaNeueThin(12.0)        upLabel.text          = "YouXianMing - iOS Programmer"        upLabel.textColor     = UIColor.whiteColor()        upLabel.textAlignment = .Center        upView.addSubview(upLabel)                weak var wself = self        timer.event({                        UIView.animateWithDuration(0.5, delay: 0, usingSpringWithDamping: 3, initialSpringVelocity: 0, options: .CurveEaseInOut, animations: {                                wself?.upView.width = CGFloat(arc4random() % 220)                                }, completion: nil)                        }, timeIntervalWithSeconds: 1, delayWithSeconds: 1)        timer.start()    }}