首先，iOS 的 launch images 只能是静态图片
启动『动画』应该实际上是两部分，那张静态 launch image 作为起点，App 实际启动后播放完整的动画。
iOS软件开发中，通常在软件启动时需要创建一个闪屏显示欢迎信息，在显示闪屏的同时可以让程序在后台进行一些初始化工作，例如，检查网络连接、读取系统 设置等，等初始化工作完成以后再显示程序主界面，这里我们使用定时器来制作闪屏，在定时器到期以后，移除闪屏，显示程序主界面，并使用UIView的动画 方法使闪屏平滑过渡到主界面显示.
这里主要用到了定时器:
//NSTimer其实是将一个监听加入的系统的RunLoop中去，当系统runloop到如何timer条件的循环时，
//会调用timer一次，当timer执行完，也就是回调函数执行之后，timer会再一次的将自己加入到runloop中去继续监听_timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(fadeScreen)userInfo:nil repeats:NO];代码:
#import "StartupScreenViewController.h"@interface StartupScreenViewController ()@end@implementation StartupScreenViewController@synthesize timer = _timer;@synthesize splashImageView = _splashImageView;@synthesize mainViewController = mainviewController; //主界面 -(void)loadView{ CGRect appFrame = [[UIScreen mainScreen] applicationFrame]; UIView *view = [[UIView alloc] initWithFrame:appFrame]; view.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth; self.view = view; [view release]; _splashImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed: @"splash.png"]]; _splashImageView.frame = CGRectMake(0, 0, 320, 480); [self.view addSubview:_splashImageView]; _viewController = [[MainViewController alloc] init]; _viewController.view.alpha = 0.0; [self.view addSubview:viewController.view]; _timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(fadeScreen) userInfo:nil repeats:NO];}- (void)fadeScreen{ [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:0.75]; [UIView setAnimationDelegate:self]; [UIView setAnimationDidStopSelector:@selector(finishedFading)]; self.view.alpha = 0.0; [UIView commitAnimations];}- (void) finishedFading{ [UIView beginAnimations:nil context:nil]; [UIView setAnimationDuration:0.75]; self.view.alpha = 1.0; viewController.view.alpha = 1.0; [UIView commitAnimations]; [_splashImageView removeFromSuperview];}例子2:- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{ self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease]; // Override point for customization after application launch. self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease]; self.window.rootViewController = self.viewController; [self.window makeKeyAndVisible]; UIImageView *splashScreen = [[[UIImageView alloc] initWithFrame:self.window.bounds] autorelease]; splashScreen.image = [UIImage imageNamed:@"Default"]; [self.window addSubview:splashScreen]; [UIView animateWithDuration:1.0 animations:^{ CATransform3D transform = CATransform3DMakeScale(1.5, 1.5, 1.0); splashScreen.layer.transform = transform; splashScreen.alpha = 0.0; } completion:^(BOOL finished) { [splashScreen removeFromSuperview]; }]; return YES;}