• 每一個(gè)UIView都默認(rèn)關(guān)聯(lián)著一個(gè)CALayer，我們成這個(gè)layer為root layer
• 所有的非root layer都存在默認(rèn)的隱式動(dòng)畫(huà)，隱式動(dòng)畫(huà)默認(rèn)為1/4秒。

iOS開(kāi)發(fā)中的動(dòng)畫(huà)分為兩種:

• 一種為UIView動(dòng)畫(huà),又稱隱式動(dòng)畫(huà),動(dòng)畫(huà)后frame的數(shù)值發(fā)生了變化。
• 另一種是CALayer動(dòng)畫(huà),又稱顯示動(dòng)畫(huà),動(dòng)畫(huà)后模型層的數(shù)據(jù)不會(huì)發(fā)生變化,圖形回到原來(lái)的位置。

但是在實(shí)際開(kāi)發(fā)中,因?yàn)閁IView可以響應(yīng)用戶交互,所以UIView動(dòng)畫(huà)用的多.

一個(gè)小小的demo：

• 點(diǎn)擊屏幕改變顏色 XXChangeColorViewController
• 點(diǎn)擊屏幕改變顏色運(yùn)用轉(zhuǎn)場(chǎng)動(dòng)畫(huà)實(shí)現(xiàn) XXCustomChangeColorViewController
• 點(diǎn)擊屏幕改變顏色，以及跟隨觸摸點(diǎn)改變位置 XXChangeColorAndFrameViewController

三個(gè)重要控制器源代碼如下
XXChangeColorViewController

#import "XXChangeColorViewController.h"

#define XXRamdomColor [UIColor colorWithRed:arc4random_uniform(255)/255.0 green:arc4random_uniform(255)/255.0 blue:arc4random_uniform(255)/255.0 alpha:1]

@interface XXChangeColorViewController ()

//顯示顏色的layer
@property (nonatomic, strong) CALayer *colorLayer;

//colorView
@property (nonatomic, strong) UIView *colorView;

@end

@implementation XXChangeColorViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.title = @"點(diǎn)擊屏幕改變顏色";
    
    //用layer實(shí)現(xiàn)
    self.colorLayer = [CALayer layer];
    self.colorLayer.frame = CGRectMake(100, 100, 100, 100);
    self.colorLayer.backgroundColor = [UIColor redColor].CGColor;
    [self.view.layer addSublayer:self.colorLayer];
    
    //用view實(shí)現(xiàn)
    UIView *colorView = [[UIView alloc] init];
    self.colorView = colorView;
    colorView.frame = CGRectMake(100, 300, 100, 100);
    colorView.backgroundColor = [UIColor redColor];
    [self.view addSubview:colorView];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    self.colorLayer.backgroundColor = XXRamdomColor.CGColor;
    self.colorView.backgroundColor = XXRamdomColor;
}



@end

XXCustomChangeColorViewController

#import "XXCustomChangeColorViewController.h"
#define XXRamdomColor [UIColor colorWithRed:arc4random_uniform(255)/255.0 green:arc4random_uniform(255)/255.0 blue:arc4random_uniform(255)/255.0 alpha:1]

@interface XXCustomChangeColorViewController ()

//colorLayer
@property (nonatomic, strong) CALayer *colorLayer;

@end

@implementation XXCustomChangeColorViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.title = @"自定義改變顏色";
    
    //用layer實(shí)現(xiàn)
    self.colorLayer = [CALayer layer];
    self.colorLayer.frame = CGRectMake(100, 100, 100, 100);
    self.colorLayer.backgroundColor = [UIColor redColor].CGColor;
    [self.view.layer addSublayer:self.colorLayer];
    
    //加入轉(zhuǎn)場(chǎng)動(dòng)畫(huà)
    CATransition *transition = [CATransition animation];
    transition.type = kCATransitionPush;
    transition.subtype = kCATransitionFromLeft;
    self.colorLayer.actions = @{@"backgroundColor": transition};
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    self.colorLayer.backgroundColor = XXRamdomColor.CGColor;
}

@end

XXChangeColorAndFrameViewController

#import "XXChangeColorAndFrameViewController.h"


#define XXRamdomColor [UIColor colorWithRed:arc4random_uniform(255)/255.0 green:arc4random_uniform(255)/255.0 blue:arc4random_uniform(255)/255.0 alpha:1]

@interface XXChangeColorAndFrameViewController ()

//colorLayer
@property (nonatomic, strong) CALayer *colorLayer;

@end

@implementation XXChangeColorAndFrameViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.title = @"改變顏色以及跟隨手勢(shì)改變位置";
    
    //用layer實(shí)現(xiàn)
    self.colorLayer = [CALayer layer];
    self.colorLayer.frame = CGRectMake(100, 100, 100, 100);
    self.colorLayer.backgroundColor = [UIColor redColor].CGColor;
    [self.view.layer addSublayer:self.colorLayer];  
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    //獲取到當(dāng)前的觸摸點(diǎn)
    CGPoint point = [[touches anyObject] locationInView:self.view];
    //如果觸摸點(diǎn)在colorLayer范圍內(nèi)，則改變顏色，否則跟隨手指改變位置
    if ([self.colorLayer.presentationLayer hitTest:point]) {
        self.colorLayer.backgroundColor = XXRamdomColor.CGColor;
    }else {
        [CATransaction begin];
        [CATransaction setAnimationDuration:4.0];
        self.colorLayer.position = point;
        [CATransaction commit];
    }
}

@end

效果如下圖

P9w9CArdI9S0hkAVHNyfnPrRjdTBKV5Y.gif