从开发者角度讲app启动当然越快越好，但是有时候总有些奇葩需求。比如，让启动页故意延时、在启动页上加个动画等等。下面我们来实现一个启动页动画。##

启动页动画

创建一个启动页文件

a: 创建iOS工程的时候默认会有个LaunchScreen.storyboard文件作为静态启动页，这里我们不用它，我们创建一个LaunchScreen.xib文件作为静态启动页。这里就不用详细说明怎么创建xib了。。。注意一下命名！！！

b：创建好LaunchScreen.xib之后，在文件中添加一个UIImageView设置好你的启动页图片。

c：删除LaunchScreen.storyboard文件

此时编译运行你就可以看到静态启动页了

代码相关

思路：在苹果粑粑的设计中，启动页应该就只是需要一张静态图就ok了，毕竟对用户使用来说，app启动越快越好。因此没有常规的方法实现启动页动画。我的想法是在启动后获取到启动页的内容然后将其填充到一个 UIViewController 中，再构建相关动画。下面说具体步骤

a: 创建 UIViewController 文件

//获取启动页文件名
lazy var launchName : String = {
        let tempLaunchName = Bundle.main.infoDictionary!["UILaunchStoryboardName"] as! String
        return tempLaunchName
    }()

//将启动页内容，并生成UIImageView
lazy var launchView : UIImageView = {
        let viewCopy = NSKeyedUnarchiver.unarchiveObject(with: NSKeyedArchiver.archivedData(withRootObject: self.view)) as! UIView
        let window = UIApplication.shared.keyWindow
        window?.addSubview(viewCopy)        
UIGraphicsBeginImageContextWithOptions(UIScreen.main.bounds.size, true, 0.0)
        viewCopy.layer.render(in: UIGraphicsGetCurrentContext()!)
        viewCopy.removeFromSuperview()
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        let launchView = UIImageView.init(image: image)
        launchView.frame = UIScreen.main.bounds
        return launchView
    }()

//构建view，并将launchView添加进去
override func viewDidLoad() {
        super.viewDidLoad()
        NSKeyedArchiver.archivedData(withRootObject: self.view)
        let app : UIApplication = UIApplication.shared;
        self.view = UINib.init(nibName: self.launchName, bundle: nil).instantiate(withOwner: self, options: nil).first as! UIView;
        self.view.layoutIfNeeded()
        app.keyWindow?.addSubview(self.launchView)
    }

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
         //TODO 启动页相关动画
        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2.5) {
        //动画结束执行相关跳转逻辑
            self.goToNextPage()
        }
    }

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        if #available(iOS 9.0, *) {
        }else{
            self.window = UIWindow.init(frame: UIScreen.main.bounds)
        }
        let launchViewController = XBLaunchViewController.init();
        self.window?.rootViewController = launchViewController;
        self.window?.makeKeyAndVisible()
        return true
    }