代码：

#import "MainViewController.h"@interface MainViewController ()@end@implementation MainViewController- (void)viewDidLoad{    [super viewDidLoad];        UIView *view1 = [[UIView alloc]initWithFrame:[[UIScreen mainScreen] bounds]];    view1.backgroundColor = [UIColor blueColor];        UIView *view2 = [[UIView alloc]initWithFrame:[[UIScreen mainScreen] bounds]];    view2.backgroundColor = [UIColor yellowColor];    [self.view addSubview:view1];    [self.view addSubview:view2];}-(void) changeView{    NSLog(@"change view");    CGContextRef context = UIGraphicsGetCurrentContext();    [UIView beginAnimations:nil context:context];    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];    [UIView setAnimationDuration:1.0];           [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];    [self.view exchangeSubviewAtIndex:0 withSubviewAtIndex:1];        [UIView setAnimationDelegate:self];    [UIView setAnimationDidStopSelector:nil];    [UIView commitAnimations];}-(void) changeView2{    CATransition *animation = [CATransition animation];    [animation setDuration:1.25f];    [animation setTimingFunction:[CAMediaTimingFunction                                  functionWithName:kCAMediaTimingFunctionEaseIn]];    [animation setType:kCATransitionReveal];    [animation setSubtype: kCATransitionFromRight];    [self.view.layer addAnimation:animation forKey:@"Reveal"];        [self.view exchangeSubviewAtIndex:0 withSubviewAtIndex:1];       [CATransaction commit];}-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    [self changeView];}@end