IOS闪屏制作——程序启动动画

进度条动画:http://blog.csdn.net/jwzbskywz/article/details/7703042

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;
}