CALayer简单应用——隐式动画

#import "ViewController.h"

#define figureWidth 50

@interface ViewController ()

@property (nonatomic,strong)CALayer *graph;

@end

@implementation ViewController

- (void)viewDidLoad {

    [superviewDidLoad];

    self.graph = [CALayerlayer];

    self.graph.bounds =CGRectMake(0,0,figureWidth,figureWidth);

    self.graph.backgroundColor = [UIColorblackColor].CGColor;

    self.graph.shadowColor = [UIColorgrayColor].CGColor;

    self.graph.shadowOffset =CGSizeMake(3.0f,3.0f);

    self.graph.shadowOpacity =0.8f;

    self.graph.cornerRadius =figureWidth/2;

    

    [self.view.layeraddSublayer:self.graph];

 }

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{

    UITouch *touch = [touchesanyObject];

    CGFloat currentWidth =self.graph.bounds.size.width;

    if (currentWidth ==figureWidth) {

        

        currentWidth = currentWidth *3;

    }else{

        

        currentWidth = figureWidth;

    }

    self.graph.bounds =CGRectMake(0,0, currentWidth, currentWidth);

    self.graph.position = [touchlocationInView:self.view];

    self.graph.cornerRadius = currentWidth/2;

}