Transform动画初解 in Swift

创建一个界面，就像这样的：

顶部是一个UISegmentControl，用来制定transform的类型。分别是：CGAffineTransformMakeTranslation、CGAffineTransformTranslate、CGAffineTransformIdentity.

然后是一个UILabel，这个Label实时的显示当前的动画类型是什么。

桔色的是动画的View。

最下面是一个按钮，按这个按钮桔色的View开始执行动画。

其他的，蓝色的线就是这几个View的Constraints。指定这几个view的定位是如何的，比如，相对于顶部的距离，相对于左边的距离，右边的距离等。

配置好页面上的View之后，给这些View在Controller中指定对应的对象。并在nib文件中指定各个View的事件。

View在controller中对应的对象：

    @IBOutlet weak var animationView: UIView!
    @IBOutlet weak var animationLabel: UILabel!

UISegmentControl的事件：

    @IBAction func segmentAction(sender: AnyObject) {
        var segmentControl = sender as UISegmentedControl
        animationType = segmentControl.selectedSegmentIndex
    }

运行动画的按钮的事件：

@IBAction func runAction(sender: AnyObject) {
        var distance: CGFloat = 30
        switch animationType {
        case 0:
            self.animationLabel.text = "CGAffineTransformMakeTranslation"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformMakeTranslation(distance, 0)
            })
        case 1:
            self.animationLabel.text = "CGAffineTransformTranslate"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformTranslate(self.animationView.transform, distance, 0)
            })
        case 2:
            self.animationLabel.text = "CGAffineTransformIdentity"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformTranslate(CGAffineTransformIdentity, distance, 0)
            })
        default:
            println("")
        }
    }

在ViewDidLoad设置选择的动画的类型，这里我们不直接取UISegmentControl的selectedIndex的值。所以，在ViewDidLoad方法内设定默认值是1（即选定到是第一个）。

全部代码：

//
//  ViewController.swift
//  TransformDemo
//
//  Created by Bruce Lee on 30/11/14.
//  Copyright (c) 2014 Dynamic Cell. All rights reserved.
//  
//  QQ:1828099940, 群:58099570 欢迎加入讨论
//

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var animationView: UIView!
    @IBOutlet weak var animationLabel: UILabel!
    
    var animationType: Int!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        animationType = 0
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func segmentAction(sender: AnyObject) {
        var segmentControl = sender as UISegmentedControl
        animationType = segmentControl.selectedSegmentIndex
    }

    @IBAction func runAction(sender: AnyObject) {
        var distance: CGFloat = 30
        switch animationType {
        case 0:
            self.animationLabel.text = "CGAffineTransformMakeTranslation"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformMakeTranslation(distance, 0)
            })
        case 1:
            self.animationLabel.text = "CGAffineTransformTranslate"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformTranslate(self.animationView.transform, distance, 0)
            })
        case 2:
            self.animationLabel.text = "CGAffineTransformIdentity"
            UIView.animateWithDuration(1.0, animations: {
                self.animationView.transform = CGAffineTransformTranslate(CGAffineTransformIdentity, distance, 0)
            })
        default:
            println("")
        }
    }
}