iOS启动屏后再加个闪屏的方法

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window.rootViewController.view.alpha = 0;
_splashImageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"Default"]];
_splashImageView.frame = [UIScreen mainScreen].bounds;
[self.window addSubview:_splashImageView];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[UIView animateWithDuration:0.5 animations:^{
self.window.rootViewController.view.alpha = 1.0;
} completion:^(BOOL finished) {
[_splashImageView removeFromSuperview];
}];
});
return YES;
}