Swift - 启动画面放大淡出效果的实现1（使用launch image）

          

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //播放启动画面动画
        launchAnimation()
    }
    
    //播放启动画面动画
    private func launchAnimation() {
        let statusBarOrientation = UIApplication.shared.statusBarOrientation
        if let img = splashImageForOrientation(statusBarOrientation,
                                               size: self.view.bounds.size) {
            //获取启动图片
            let launchImage = UIImage(named: img)
            let launchview = UIImageView(frame: UIScreen.main.bounds)
            launchview.image = launchImage
            //将图片添加到视图上（分两种情况）
            //情况1:没有导航栏
            //self.view.addSubview(launchview)
            //情况2:有导航栏
            let delegate = UIApplication.shared.delegate
            let mainWindow = delegate?.window
            mainWindow!!.addSubview(launchview)
            
            //播放动画效果，完毕后将其移除
            UIView.animate(withDuration: 1, delay: 1.5, options: .beginFromCurrentState,
                           animations: {
                            launchview.alpha = 0.0
                            launchview.layer.transform = CATransform3DScale(
                                CATransform3DIdentity, 1.5, 1.5, 1.0)
            }) { (finished) in
                launchview.removeFromSuperview()
            }
        }
    }
    
    //获取启动图片名（根据设备方向和尺寸）
    func splashImageForOrientation(_ orientation: UIInterfaceOrientation, size: CGSize)
        -> String?{
        //获取设备尺寸和方向
        var viewSize = size
        var viewOrientation = "Portrait"
        
        if UIInterfaceOrientationIsLandscape(orientation) {
            viewSize = CGSize(width: size.height, height: size.width)
            viewOrientation = "Landscape"
        }
        
        //遍历资源库中的所有启动图片，找出符合条件的
        if let imagesDict = Bundle.main.infoDictionary  {
            if let imagesArray = imagesDict["UILaunchImages"] as? [[String: String]] {
                for dict in imagesArray {
                    if let sizeString = dict["UILaunchImageSize"],
                        let imageOrientation = dict["UILaunchImageOrientation"] {
                        let imageSize = CGSizeFromString(sizeString)
                        if imageSize.equalTo(viewSize)
                            && viewOrientation == imageOrientation {
                            if let imageName = dict["UILaunchImageName"] {
                                return imageName
                            }
                        }
                    }
                }
            }
        }
        
        return nil
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}