CALayer

1、CALayer

一、CALayer通常做爲UIViewiew的容器使用

二、CALayer是一個管理着圖片載體的層結構

三、直接修改單首創建出的CALayer的屬性能夠觸發隱式動畫

四、UIview中的CALayer動畫必須顯示觸發才能生效

 例1、

@property(nonatomic,strong)CALayer * layer;

- (void)viewDidLoad {

    [super viewDidLoad];

    UIView * containerView=[[UIView alloc]initWithFrame:CGRectMake(100, 100, 100, 3)];

    containerView.backgroundColor=[UIColor redColor];

    [self.view addSubview:containerView];

    

    self.layer=[CALayer layer];

    self.layer.frame=CGRectMake(0, 0, 0, 3);

    self.layer.backgroundColor=[UIColor greenColor].CGColor;

    [containerView.layer addSublayer:self.layer];

    

    [self performSelector:@selector(layerAnimation) withObject:nil afterDelay:3.0f];

}

 

-(void)layerAnimation

{

    self.layer.frame=CGRectMake(0, 0, 50, 3);

}

如圖作隱式動畫的緩衝進度條

 

例二：

 自定義一個view

ProgressView.h文件

@interface ProgressView : UIView

@property(nonatomic,assign)CGFloat progress;//進度參數

@end

ProgressView.m文件

#import "ProgressView.h"

/**

 存放不想讓外部類訪問的變量

 */

 

@interface ProgressView ()

@property(nonatomic,strong)CALayer * progressLayer;

@property(nonatomic,assign)CGFloat currentViewWidth;

@end

 

@implementation ProgressView

 

- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self) {

        self.progressLayer=[CALayer layer];

        self.progressLayer.frame=CGRectMake(0, 0, 0, frame.size.height);

        self.progressLayer.backgroundColor=[UIColor greenColor].CGColor;

        [self.layer addSublayer:self.progressLayer];

        

        //存儲當前view的寬度值

        self.currentViewWidth=frame.size.width;

    }

    return self;

}

/**

 *  重寫setter，getter方法

 */

@synthesize progress=_progress;

-(void)setProgress:(CGFloat)progress

{

    _progress=progress;

    if (progress<=0) {

        self.progressLayer.frame=CGRectMake(0, 0, 0, self.frame.size.height);

    }else if(progress<=1)

    {

        self.progressLayer.frame=CGRectMake(0, 0, progress*self.currentViewWidth, self.frame.size.height);

    }

}

-(CGFloat)progress

{

    return _progress;

}

@end

 viewcontroller裏：

@property(nonatomic,retain)ProgressView * progressview;

@property(nonatomic,retain)NSTimer * timer;

- (void)viewDidLoad {

    [super viewDidLoad];

    

    self.progressview=[[ProgressView alloc]initWithFrame:CGRectMake(20, 100, 290, 5)];

    self.progressview.layer.borderWidth=1.0f;

    [self.view addSubview:self.progressview];

    

    [self performSelector:@selector(layerAnimation) withObject:nil afterDelay:3.0f];

    self.timer=[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(layerAnimation) userInfo:nil repeats:YES];

   }

 -(void)layerAnimation

{

    self.progressview.progress=arc4random()% 100/100.f;

}

2、CALayer作漸變更畫

例1、

- (void)viewDidLoad {

    [super viewDidLoad];

    UIImage * image1=[UIImage imageNamed:@"ic_empty"];

    self.imageLayer=[CALayer layer];

    self.imageLayer.frame=CGRectMake(0, 100, 100, 100);

    [self.view.layer addSublayer:self.imageLayer];

    

    self.imageLayer.contents=(__bridge id)((image1.CGImage));

    [self performSelector:@selector(layerAnimation) withObject:nil afterDelay:3.0f];

      }

-(void)layerAnimation

{

    UIImage * image2=[UIImage imageNamed:@"ic_error"];

    self.imageLayer.contents=(__bridge id )((image2.CGImage));

}

例2、

- (void)viewDidLoad {

    [super viewDidLoad];

    UIImage * image1=[UIImage imageNamed:@"ic_empty"];

    self.imageLayer=[CALayer layer];

    self.imageLayer.frame=CGRectMake(0, 100, 100, 100);

    [self.view.layer addSublayer:self.imageLayer];

    

    self.imageLayer.contents=(__bridge id)((image1.CGImage));

    [self performSelector:@selector(layerAnimation) withObject:nil afterDelay:3.0f];

          }

-(void)layerAnimation

{

    //圖片動畫

    UIImage * image2=[UIImage imageNamed:@"ic_error"];

    CABasicAnimation *animation=[CABasicAnimation animationWithKeyPath:@"contents"];

    animation.fromValue=self.imageLayer.contents;

    animation.toValue=(__bridge id )((image2.CGImage));

    animation.duration=3.0f;

    

    //bounds動畫

    CABasicAnimation * boundsAnimation=[CABasicAnimation animationWithKeyPath:@"bounds"];

    boundsAnimation.fromValue=[NSValue valueWithCGRect:self.imageLayer.bounds];

    boundsAnimation.toValue=[NSValue valueWithCGRect:CGRectMake(0, 100, 50, 50)];

    boundsAnimation.duration=3.0f;

    

    //組合動畫

    CAAnimationGroup * groupAnimation=[CAAnimationGroup animation];

    groupAnimation.animations=@[animation,boundsAnimation];

    groupAnimation.duration=3.0f;

    

    //設定layer動畫結束以後的值（必須設定，不然會恢復到動畫以前的狀態）

    self.imageLayer.contents=(__bridge id )((image2.CGImage));

    self.imageLayer.bounds=CGRectMake(0, 100, 50, 50);

    

    //提交動畫

    [self.imageLayer addAnimation:groupAnimation forKey:nil];

    

}

 建立遮罩

 self.imageContents=[UIImage imageNamed:@"ic_empty"];

    self.maskContents=[UIImage imageNamed:@"ic_error"];

    

    self.imageLayer=[CALayer layer];

    self.imageLayer.frame=CGRectMake(50, 50, 200, 200);

    self.imageLayer.contents=(__bridge id)((self.imageContents.CGImage));

    [self.view.layer addSublayer:self.imageLayer];

    

    self.maskLayer=[CALayer layer];

    self.maskLayer.frame=self.imageLayer.bounds;

  //  self.maskLayer.contents=(__bridge id )((self.maskContents.CGImage));

    self.maskLayer.backgroundColor=[UIColor blackColor].CGColor;

    

    self.imageLayer.mask=self.maskLayer;