CALayer 简单用法

首先了解一下CALayer的基本常用的属性：

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
    
    button.frame = CGRectMake(100, 50, 175, 175);
    
    [button setBackgroundImage:[UIImage imageNamed:@"06.jpg"] forState:UIControlStateNormal];
    
    [self.view addSubview:button];
    
    button.layer.cornerRadius = 20 ;
    
    button.layer.borderColor = [[UIColor yellowColor]CGColor];
    
    button.layer.borderWidth = 2 ;
    
//    button.clipsToBounds = YES ;

    //阴影颜色
    button.layer.shadowColor = [[UIColor blackColor]CGColor];
    
    //阴影的偏移距离
    button.layer.shadowOffset = CGSizeMake(20, 20);
    
    //阴影的透明度
    button.layer.shadowOpacity = 0.8 ;
    
    //阴影
    button.layer.shadowRadius = 20 ;
    
    //是否裁剪边框之外的
//    button.layer.masksToBounds = YES ;
    
    
    //CALayer负责视图的渲染 UI中真正负责绘图的部分 没有用户交互，仅仅是展示视图内容，一般用来做动画
    CALayer *layer = [CALayer layer];
    
    layer.frame = CGRectMake(100, 300, 175, 175);
    
    layer.backgroundColor = [[UIColor yellowColor]CGColor];
    
    layer.contents = (id)[[UIImage imageNamed:@"06.jpg"]CGImage];
    
    [self.view.layer addSublayer:layer];
    
    layer.shadowOffset = CGSizeMake(20, 20);
    
    layer.shadowColor = [[UIColor redColor]CGColor];
    
    layer.shadowOpacity = 0.3 ;
 
    
}

以上就是CALayer常用的属性，接下来我们用CALayer写个动画的小Demo

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic,retain) CALayer *layer ;

@end

@implementation ViewController

-(void)dealloc{
    
    [_layer release];
    [super dealloc];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    self.layer = [CALayer layer];
    
    self.layer.bounds = CGRectMake(0, 0, 100, 100);

    //设置锚点
    self.layer.position = CGPointMake(187.5, 200);
    
    //设置锚点在layer上的比例
    self.layer.anchorPoint = CGPointMake(0.2, 0.2) ;
    
    self.layer.cornerRadius = 20 ;
    
    self.layer.borderWidth = 2 ;
    
    self.layer.shadowOffset = CGSizeMake(20, 20);
    
    self.layer.shadowOpacity = 0.2 ;
    
    self.layer.doubleSided = YES ;
    
    self.layer.borderColor = [[UIColor redColor]CGColor];
    
    self.layer.backgroundColor = [[UIColor brownColor]CGColor];
    
    [self.view.layer addSublayer:self.layer];
    
    [_layer release];
    
}

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


#pragma mark -- 平移CALayer
- (IBAction)buttonAction1:(UIButton *)sender {

    //创建一个基本动画对象
    CABasicAnimation *animation = [CABasicAnimation animation];
    
    //动画的类型
    //keyPath layer的某个属性
    animation.keyPath = @"position";
    
    //动画的持续时间
    animation.duration = 2 ;
    
    //toValue 就是一个临时值,通过CALayer做的动画不会改变layer属性本身的值
    animation.toValue = [NSValue valueWithCGPoint:CGPointMake(100, 400)];
    
    //如果要保留动画的最终目的，下面两个属性分都需要设置
    
    //保持动画的最新状态
    animation.fillMode = kCAFillModeBackwards ;
    
    //设置动画完成后之后不删除
    animation.removedOnCompletion = NO ;
    
    animation.delegate = self ;
    
    [self.layer addAnimation:animation forKey:nil];
    
    
    
}

-(void)animationDidStart:(CAAnimation *)anim
{
    
    NSLog(@"%@",NSStringFromCGRect(self.layer.bounds));
    
}


#pragma mark --实现缩放
- (IBAction)buttonAction2:(UIButton *)sender {
    
    //1.创建一个基本动画
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"bounds"];
    
    //2.设置动画持续时间
    animation.duration = 2 ;
    
    //3.设置动画的最终效果
    animation.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, 200, 200)];
    
    //4.使动画保留最终状态
    animation.fillMode = kCAFillModeForwards ;
    
    animation.removedOnCompletion = NO ;
    
    //5.将动画对象付给layer
    [self.layer addAnimation:animation forKey:nil];
    
}

- (IBAction)buttonAction3:(UIButton *)sender {
    
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    
    animation.duration = 2 ;
    
    animation.fillMode = kCAFillModeForwards ;
    
    animation.removedOnCompletion = NO ;
    
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI / 3, 0, 0, 1)];
    
    [self.layer addAnimation:animation forKey:nil];
    
    
}