為iOS App增加啟動漸層效果

由於目前蘋果沒有支援該功能，所以只能自己在App啟動後做一個過度效果：

[cpp] - (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];  www.2cto.com         [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; } 
其實我覺得這個功能最好是用在兩個介面進行切換時使用，而且其中的黑屏效果如果使用view.backgroundcolor=[uicolor blackcolr];這樣就不需要一個圖片來做這種轉場效果，速度更快，占空間更小。