I'm sometimes asked how to implement the background of an app I'm making called Four Choice Chemistry, so I wrote a sample code for it.
The icon image of the app flows through the background of the View.
Also, if you write animation-related methods in viewDidLoad, animations may stop due to navigation bar transitions.
In this case, writing the animation-related methods to viewWillAppear solves the problem.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import UIKit | |
| class ViewController: UIViewController { | |
| var imageArray:Array<UIImageView> = Array() | |
| override func viewDidLoad() { | |
| super.viewDidLoad() | |
| self.view.backgroundColor = .white | |
| let viewWidth:CGFloat = self.view.frame.width | |
| let viewHeight:CGFloat = self.view.frame.height | |
| //インスタンスの生成 | |
| for i in 0..<9 { | |
| let imgView:UIImageView = UIImageView() | |
| imgView.image = UIImage(named: "AppIcon") | |
| imgView.contentMode = .scaleAspectFit | |
| imgView.frame.size = CGSize(width: 200, height: 200) | |
| imageArray.append(imgView) | |
| self.view.addSubview(imageArray[i]) | |
| } | |
| //アニメーション | |
| //１列目 | |
| imageArray[0].center = CGPoint(x: -viewWidth / 2, y: viewHeight * 0.6) | |
| imageArray[1].center = CGPoint(x: 0, y: viewHeight * 0.3) | |
| imageArray[2].center = CGPoint(x: viewWidth / 2, y: 0) | |
| //2列目 | |
| imageArray[3].center = CGPoint(x: -viewWidth / 2, y: viewHeight * 1.2) | |
| imageArray[4].center = CGPoint(x: 0, y: viewHeight * 0.9) | |
| imageArray[5].center = CGPoint(x: viewWidth / 2, y: viewHeight * 0.6) | |
| imageArray[6].center = CGPoint(x: viewWidth, y: viewHeight * 0.3) | |
| //３列目 | |
| imageArray[7].center = CGPoint(x: viewWidth / 2, y: viewHeight * 1.2) | |
| imageArray[8].center = CGPoint(x: viewWidth, y: viewHeight * 0.9) | |
| //アニメーションの設定 | |
| //4秒間かけて、一定の速さで繰り返しのアニメーションを行う | |
| UIView.animate(withDuration: 4, delay: 0.0, options: [.repeat, .curveLinear], animations: { | |
| //１列目 | |
| self.imageArray[0].center = CGPoint(x: 0, y: viewHeight * 0.3) | |
| self.imageArray[1].center = CGPoint(x: viewWidth / 2, y: 0) | |
| self.imageArray[2].center = CGPoint(x: viewWidth, y: -viewHeight * 0.3) | |
| //2列目 | |
| self.imageArray[3].center = CGPoint(x: 0, y: viewHeight * 0.9) | |
| self.imageArray[4].center = CGPoint(x: viewWidth / 2, y: viewHeight * 0.6) | |
| self.imageArray[5].center = CGPoint(x: viewWidth, y: viewHeight * 0.3) | |
| self.imageArray[6].center = CGPoint(x: viewWidth * 1.5, y: 0) | |
| //３列目 | |
| self.imageArray[7].center = CGPoint(x: viewWidth, y: viewHeight * 0.9) | |
| self.imageArray[8].center = CGPoint(x: viewWidth * 1.5, y: viewHeight * 0.6) | |
| },completion:nil) | |
| } | |
| } |