核心动画(转场动画和组动画)-转

一.转场动画简单介绍 
CAAnimation的子类，用于做转场动画，能够为层提供移出屏幕和移入屏幕的动画效果。ios比Max OS X的转场动画效果少一点。 
UINavigationController就是通过CATransition实现了将控制器的视图推入屏幕的动画效果。 

属性解析: 
type：动画过渡方向 
subtype：动画过渡方向 
strartProgress：动画起点(在整体动画的百分比) 
endProgress：动画终点(在整体动画的百分比)

二.转场动画代码示例

#import "ViewController.h"

@interface ViewController (){
    NSMutableArray *colorArray;
}
@property(nonatomic,assign) int index;
@property(nonatomic,strong) UIView *iconView;
@property(nonatomic,strong) UIButton *previousButton;
@property(nonatomic,strong) UIButton *nextButton;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    if (colorArray == nil) {
        colorArray = [[NSMutableArray alloc] init];
    }
    [colorArray addObject:[UIColor redColor]];
    [colorArray addObject:[UIColor blueColor]];
    [colorArray addObject:[UIColor greenColor]];
    [colorArray addObject:[UIColor yellowColor]];
    [colorArray addObject:[UIColor grayColor]];

    _iconView = [[UIView alloc] initWithFrame:CGRectMake([UIScreen mainScreen].bounds.size.width/2 - 280/2,
                                                         100,
                                                         280,
                                                         200)];
    _iconView.backgroundColor = [UIColor brownColor];
    [self.view addSubview:_iconView];

    _previousButton = [[UIButton alloc] initWithFrame:CGRectMake(_iconView.frame.origin.x,
                                                                 350,
                                                                 60,
                                                                 40)];
    [_previousButton setTitle:@"上一张" forState:UIControlStateNormal];
    [_previousButton setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [_previousButton addTarget:self
                        action:@selector(previousClick)
              forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:_previousButton];

    _nextButton = [[UIButton alloc] initWithFrame:CGRectMake(_iconView.frame.origin.x + _iconView.frame.size.width - 60,
                                                             350,
                                                             60,
                                                             40)];
    [_nextButton setTitle:@"下一张" forState:UIControlStateNormal];
    [_nextButton setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
    [_nextButton addTarget:self
                    action:@selector(nextButtonClick)
          forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:_nextButton];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    _index = 0;
}

#pragma mark -按钮事件
- (void)previousClick{
    _index--;
    if (_index < 0) {
        _index = 4;
    }
    _iconView.backgroundColor = [colorArray objectAtIndex:_index];
    //创建核心动画
    CATransition *animation = [CATransition animation];
    //告诉要执行什么动画
    //设置过度效果
    animation.type = @"cube";
    //设置动画的过度方向(向左)
    animation.subtype = kCATransitionFromLeft;
    //设置动画的时间
    animation.duration = 2.0;
    //添加动画
    [_iconView.layer addAnimation:animation forKey:nil];
}

- (void)nextButtonClick{
    _index++;
    if (_index > 4) {
        _index = 0;
    }
    _iconView.backgroundColor = [colorArray objectAtIndex:_index];
    //创建核心动画
    CATransition *animation = [CATransition animation];
    //告诉要执行什么动画
    //设置过度效果
    animation.type = @"cube";
    //设置动画的过度方向(向左)
    animation.subtype = kCATransitionFromRight;
    //设置动画的时间
    animation.duration = 2.0;
    //设置动画的起点
    //animation.startProgress = 0.5;
    //设置动画的终点
    //animation.endProgress = 0.5;
    //添加动画
    [_iconView.layer addAnimation:animation forKey:nil];
}
@end

三.组动画简单说明 
CAAnimation的子类，可以保存一组动画对象，将CAAnimationGroup对象加入层后，组中所有动画对象可以同时并发运行。 
属性解析：animation：用来保存一组动画对象NSArray 默认情况下，一组动画对象是同时运行的，也可以通过设置动画对象的beginTime属性更改动画的开始时间。

四.分组动画代码示例

#import "ViewController.h"

@interface ViewController ()
@property(nonatomic,strong) UIView *iconView;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    _iconView = [[UIView alloc] initWithFrame:CGRectMake(160,
                                                         40,
                                                         100,
                                                         100)];
    _iconView.backgroundColor = [UIColor redColor];
    [self.view addSubview:_iconView];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //平移动画
    CABasicAnimation *animation1 = [CABasicAnimation animation];
    animation1.keyPath = @"transform.translation.y";
    animation1.toValue = @(100);
    //缩放动画
    CABasicAnimation *animation2 = [CABasicAnimation animation];
    animation2.keyPath = @"transform.scale";
    animation2.toValue = @(0.0);
    //旋转动画
    CABasicAnimation *animation3 = [CABasicAnimation animation];
    animation3.keyPath = @"transform.rotation";
    animation3.toValue = @(M_PI_2);

    //组动画
    CAAnimationGroup *groupAnimation = [CAAnimationGroup animation];
    groupAnimation.animations = @[animation1,animation2,animation3];
    groupAnimation.duration = 2;
    groupAnimation.repeatCount = MAXFLOAT;
    groupAnimation.fillMode = kCAFillModeForwards;
    groupAnimation.removedOnCompletion = NO;
    [_iconView.layer addAnimation:groupAnimation forKey:nil];
}

@end