CALayerDelegate的實現(IOS)，calayerdelegateios

CALayerDelegate的實現(IOS)，calayerdelegateios
CALayerDelegate的實現(IOS)by 伍雪穎

- (void)viewDidLoad {
    [superviewDidLoad];
    CALayer *blueLayer = [CALayerlayer];
    blueLayer.frame =CGRectMake(50,50,100,100);
    blueLayer.backgroundColor = [UIColorblueColor].CGColor;
    [self.layerView.layeraddSublayer:blueLayer];
   
    blueLayer.delegate =self;
    blueLayer.contentsScale = [UIScreenmainScreen].scale;
   
    [blueLayer display];
}

- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
    CGContextSetLineWidth(ctx,10);
    CGContextSetStrokeColorWithColor(ctx, [UIColorredColor].CGColor);
    CGContextStrokeEllipseInRect(ctx, layer.bounds);}