学习文章
效果
ScaleLabel.gif
简单原理
创建一个 ScaleLabel 的 View , View 上有两个 UILabel , 一个 Label 负责文本呈现,另一个 Label 负责缩放颜色的呈现.利用仿射的缩放变换和颜色透明度的变化,在 UIView 的动画中生动的变现出来.
源码
ScaleLabel.swift
import UIKit
class ScaleLabel: UIView {
var m_text : String? {
willSet {
m_backLabel.text = newValue
m_colorLabel.text = newValue
}
}
var m_font : UIFont? {
willSet {
m_backLabel.font = newValue
m_colorLabel.font = newValue
}
}
var m_startScale : Float? {
willSet {
m_backLabel.transform = CGAffineTransformMake(CGFloat(newValue!), 0, 0, CGFloat(newValue!), 0, 0)
m_colorLabel.transform = CGAffineTransformMake(CGFloat(newValue!), 0, 0, CGFloat(newValue!), 0, 0)
}
}
var m_endScale : Float?
var m_backLabelColor : UIColor? {
willSet {
m_backLabel.textColor = newValue
}
}
var m_colorLabelColor : UIColor? {
willSet {
m_colorLabel.textColor = newValue
}
}
private
var m_backLabel : UILabel!
private
var m_colorLabel : UILabel!
func startAnimation() {
if(self.m_endScale == 0) {
self.m_endScale = 2.0
}
[UIView .animateWithDuration(1, delay: 0, usingSpringWithDamping: 7, initialSpringVelocity: 4, options: .CurveEaseInOut, animations: { [weak self]() -> Void in
if let strongSelf = self {
strongSelf.m_backLabel.alpha = 1.0
strongSelf.m_backLabel.transform = CGAffineTransformIdentity
strongSelf.m_colorLabel.alpha = 1.0
strongSelf.m_colorLabel.transform = CGAffineTransformIdentity
}
}, completion: { (Bool) -> Void in
[UIView .animateWithDuration(2, delay: 0.5, usingSpringWithDamping: 7, initialSpringVelocity: 4, options: .CurveEaseInOut, animations: { () -> Void in
self.m_colorLabel.alpha = 0
self.m_colorLabel.transform = CGAffineTransformMake(CGFloat(self.m_endScale!), 0, 0, CGFloat(self.m_endScale!), 0, 0)
}, completion: nil)]
})]
}
override init(frame: CGRect) {
super.init(frame: frame)
self.m_backLabel = UILabel(frame: self.bounds)
self.m_colorLabel = UILabel(frame: self.bounds)
self.addSubview(self.m_backLabel)
self.addSubview(self.m_colorLabel)
self.m_backLabel.alpha = 0
self.m_colorLabel.alpha = 0
self.m_backLabel.textAlignment = .Center
self.m_colorLabel.textAlignment = .Center
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
ViewController.swift
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.blackColor()
let scaleLabel1 :ScaleLabel = ScaleLabel(frame: CGRect(x: 0, y: 80, width: 300, height: 50))
scaleLabel1.m_text = "刘大帅"
scaleLabel1.m_startScale = 0.3
scaleLabel1.m_endScale = 2
scaleLabel1.m_backLabelColor = UIColor.whiteColor()
scaleLabel1.m_colorLabelColor = UIColor.cyanColor()
scaleLabel1.m_font = UIFont(name: "Avenir-Light", size: 20)
self.view.addSubview(scaleLabel1)
let scaleLabel2 :ScaleLabel = ScaleLabel(frame: CGRect(x: 0, y: 180, width: 300, height: 50))
scaleLabel2.m_text = "Frank Liu"
scaleLabel2.m_startScale = 0.3
scaleLabel2.m_endScale = 2
scaleLabel2.m_backLabelColor = UIColor.cyanColor()
scaleLabel2.m_colorLabelColor = UIColor.purpleColor()
scaleLabel2.m_font = UIFont(name: "Avenir-Light", size: 20)
self.view.addSubview(scaleLabel2)
let scaleLabel3 :ScaleLabel = ScaleLabel(frame: CGRect(x: 0, y: 280, width: 300, height: 50))
scaleLabel3.m_text = "You Xian Ming"
scaleLabel3.m_startScale = 0.3
scaleLabel3.m_endScale = 2
scaleLabel3.m_backLabelColor = UIColor.purpleColor()
scaleLabel3.m_colorLabelColor = UIColor.orangeColor()
scaleLabel3.m_font = UIFont(name: "Avenir-Light", size: 20)
self.view.addSubview(scaleLabel3)
// 执行动画
GCDQueue.mainQueue().execute({ () -> Void in
scaleLabel1.startAnimation()
scaleLabel2.startAnimation()
scaleLabel3.startAnimation()
}, afterDelaySecs: 1)
}
}
