最普通动画:
//开始动画
[UIView beginAnimations:nil context:nil];  
//设定动画持续时间
[UIView setAnimationDuration:2];
//动画的内容
frame.origin.x += 150;
[img setFrame:frame];
//动画结束
[UIView commitAnimations];

连续动画:一个接一个地显示一系列的图像
NSArray *myImages = [NSArray arrayWithObjects: 
[UIImage imageNamed:@"myImage1.png"], 
[UIImage imageNamed:@"myImage2.png"], 
[UIImage imageNamed:@"myImage3.png"], 
[UIImage imageNamed:@"myImage4.gif"], nil];

UIImageView *myAnimatedView = [UIImageView alloc]; 
[myAnimatedView initWithFrame:[self bounds]]; 
myAnimatedView.animationImages = myImages; //animationImages属性返回一个存放动画图片的数组
myAnimatedView.animationDuration = 0.25; //浏览整个图片一次所用的时间
myAnimatedView.animationRepeatCount = 0; // 0 = loops forever 动画重复次数
[myAnimatedView startAnimating]; 
[self addSubview:myAnimatedView]; 
[myAnimatedView release]; 

CATransition Public API动画:
CATransition *animation = [CATransition animation];
//动画时间
    animation.duration = 0.5f;
//先慢后快
    animation.timingFunction = UIViewAnimationCurveEaseInOut;
animation.fillMode = kCAFillModeForwards;
//animation.removedOnCompletion = NO;

//各种动画效果
/*
kCATransitionFade;
kCATransitionMoveIn;
kCATransitionPush;z
kCATransitionReveal;
*/
/*
kCATransitionFromRight;
kCATransitionFromLeft;
kCATransitionFromTop;
kCATransitionFromBottom;
*/
//各种组合
animation.type = kCATransitionPush;
animation.subtype = kCATransitionFromRight; 

[self.view.layer addAnimation:animation forKey:@"animation"];

CATransition Private API动画:
animation.type可以设定为以下效果
动画效果汇总:
/*
 suckEffect（三角）

 rippleEffect（水波抖动）

 pageCurl（上翻页）

 pageUnCurl（下翻页）

 oglFlip（上下翻转）

 cameraIris/cameraIrisHollowOpen/cameraIrisHollowClose  （镜头快门，这一组动画是有效果，只是很难看，不建议使用



UIView Animations 动画:
[UIView beginAnimations:@"animationID" context:nil];
[UIView setAnimationDuration:0.5f];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationRepeatAutoreverses:NO];
//以下四种效果
/*
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.view cache:YES];//oglFlip, fromLeft 
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];//oglFlip, fromRight  
[UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:self.view cache:YES];
[UIView setAnimationTransition:UIViewAnimationTransitionCurlDown forView:self.view cache:YES];
*/

[self.view exchangeSubviewAtIndex:1 withSubviewAtIndex:0];
[UIView commitAnimations];
IOS4.0新方法:
方法: +(void)animateWithDuration:(NSTimeInterval)duration animations:(void (^)(void))animations;
+ (void)animateWithDuration:(NSTimeInterval)duration animations:(void (^)(void))animations completion:(void (^)(BOOL finished))completion; //多一个动画结束后可以执行的操作.

//下边是嵌套使用,先变大再消失的动画效果.
[UIView animateWithDuration:1.25 animations:^{
CGAffineTransform newTransform = CGAffineTransformMakeScale(1.2, 1.2);
[firstImageView setTransform:newTransform];
[secondImageView setTransform:newTransform];} 
completion:^(BOOL finished){
[UIView animateWithDuration:1.2 animations:^{
[firstImageView setAlpha:0];
[secondImageView setAlpha:0];} completion:^(BOOL finished){ 
[firstImageView removeFromSuperview]; 
[secondImageView removeFromSuperview]; }]; 
}];