新建一个view-based模板工程，在ViewController文件中添加下面的代码，即可实现翻转效果；
- (void)viewDidLoad {
[super viewDidLoad];
//需要翻转的视图
UIView *parentView = [[UIView alloc] initWithFrame:CGRectMake(0, 150, 320, 200)];
parentView.backgroundColor = [UIColor yellowColor];
parentView.tag = 1000;
[self.view addSubview:parentView];
}
//需要在h头文件声明下面的动作响应函数
//在xib文件中添加一个button，其响应函数为下面的函数
//运行程序后，点击button就看到翻转效果
-(IBAction)ActionFanzhuan{
//获取当前画图的设备上下文
CGContextRef context = UIGraphicsGetCurrentContext();
//开始准备动画
[UIView beginAnimations:nil context:context];
//设置动画曲线，翻译不准，见苹果官方文档
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
//设置动画持续时间
[UIView setAnimationDuration:1.0];
//因为没给viewController类添加成员变量，所以用下面方法得到viewDidLoad添加的子视图
UIView *parentView = [self.view viewWithTag:1000];
//设置动画效果
[UIView setAnimationTransition: UIViewAnimationTransitionCurlDown forView:parentView cache:YES]; //从上向下
// [UIView setAnimationTransition: UIViewAnimationTransitionCurlUp forView:parentView cache:YES]; //从下向上
// [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromLeft forView:parentView cache:YES]; //从左向右
// [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromRight forView:parentView cache:YES];//从右向左
//设置动画委托
[UIView setAnimationDelegate:self];
//当动画执行结束，执行animationFinished方法
[UIView setAnimationDidStopSelector:@selector(animationFinished:)];
//提交动画
[UIView commitAnimations];
}
//动画效果执行完毕
- (void) animationFinished: (id) sender{
NSLog(@"animationFinished !");
}
运行程序，点击按钮，就能看到动画效果了
下面我自己在parentView上添加了两个子视图实现动画
- (void)viewDidLoad {
[super viewDidLoad];
UIView *parentView = [[UIView alloc] initWithFrame:CGRectMake(0, 150, 320, 200)];
parentView.backgroundColor = [UIColor yellowColor];
parentView.tag = 1000;
UIImageView *image1 = [[UIImageView alloc] initWithFrame:CGRectMake(50, 50, 100, 100)];
image1.backgroundColor = [UIColor redColor];
image1.tag = 1001;
UIImageView *image2 = [[UIImageView alloc] initWithFrame:CGRectMake(50, 50, 100, 100)];
image2.backgroundColor = [UIColor blueColor];
image2.tag = 1002;
[parentView addSubview:image1];
[parentView addSubview:image2];
[self.view addSubview:parentView];
}
-(IBAction)ActionFanzhuan{
CGContextRef context = UIGraphicsGetCurrentContext();
[UIView beginAnimations:nil context:context];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration:1.0];
UIView *parentView = [self.view viewWithTag:1000];
[UIView setAnimationTransition: UIViewAnimationTransitionCurlDown forView:parentView cache:YES];
// [UIView setAnimationTransition: UIViewAnimationTransitionCurlUp forView:parentView cache:YES];
// [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromLeft forView:parentView cache:YES];
// [UIView setAnimationTransition: UIViewAnimationTransitionFlipFromRight forView:parentView cache:YES];
NSInteger purple = [[parentView subviews] indexOfObject:[parentView viewWithTag:1002]];
NSInteger maroon = [[parentView subviews] indexOfObject:[parentView viewWithTag:1001]];
[parentView exchangeSubviewAtIndex:purple withSubviewAtIndex:maroon];
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:@selector(animationFinished:)];
[UIView commitAnimations];
}
- (void) animationFinished: (id) sender{
NSLog(@"animationFinished !");
}
另外：之前在viewDidLoad里面写实现动画的代码，但一致未实现动画效果，原来在viewDidLoad里面执行
CGContextRef context = UIGraphicsGetCurrentContext();
后context的指针为0