CoreAnimation----CAShapeLayer

大美女

先說說使用CAShapeLayer的優(yōu)點(diǎn): GPU執(zhí)行, GPU執(zhí)行, GPU執(zhí)行

CAShapeLayer

1. CAShapeLayer的優(yōu)點(diǎn)

• 渲染迅速，硬件加速GPU執(zhí)行 。
• 內(nèi)存利用率高，不需要寄宿圖，所以比CALayer的內(nèi)存占用還低。 。
• 圖層邊界不會(huì)被裁減掉，CAShapeLayer可在邊界外進(jìn)行繪制
• 不會(huì) 像素化

2. 使用CGPath

1. CAShapeLayer可繪制所有通過CGPath表示的形狀
2. 這個(gè)形狀不一定要閉合
3. 可控制屬性如：lineWidth(線寬)，lineCap(線條結(jié)尾的樣式)，lineJoin(線條之間結(jié)合點(diǎn)的樣式)

使用CAShapeLayer畫“火柴人”：

- (void)viewDidLoad {

 [super  viewDidLoad];

  UIBezierPath *path = [UIBezierPath  bezierPath];

 [path moveToPoint:CGPointMake(175, 100)];

 [path addArcWithCenter:CGPointMake(150, 100) radius:25  startAngle:0  endAngle:M_PI * 2  clockwise:YES];

 [path moveToPoint:CGPointMake(150, 125)];

 [path addLineToPoint:CGPointMake(150, 175)];

 [path addLineToPoint:CGPointMake(125, 225)];

 [path moveToPoint:CGPointMake(150, 175)];

 [path addLineToPoint:CGPointMake(175, 225)];

 [path moveToPoint:CGPointMake(100, 150)];

 [path addLineToPoint:CGPointMake(200, 150)];

  CAShapeLayer *shapeLayer = [CAShapeLayer  layer];

 shapeLayer.strokeColor = [UIColor  redColor].CGColor;

 shapeLayer.fillColor = [UIColor  clearColor].CGColor;

 shapeLayer.lineWidth = 5.0f;

 shapeLayer.lineJoin = @"round";

 shapeLayer.lineCap = @"round";

 shapeLayer.path = path.CGPath;

 [self.view.layer addSublayer:shapeLayer];

  NSLog(@"-------viewDidlod-------");

}

3. 圓角

• 除了設(shè)置CALayer的cornerRadius，還可以單獨(dú)設(shè)置一個(gè)角的圓角
  設(shè)置矩形的三個(gè)角為圓角

- (void)viewDidLoad {

 [super  viewDidLoad];

 CGRect tect = CGRectMake(50, 50, 100, 100);

 CGSize radii = CGSizeMake(20, 20);

  UIRectCorner corner = UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight;

  UIBezierPath *path = [UIBezierPath  bezierPathWithRoundedRect:tect byRoundingCorners:corner cornerRadii:radii];

  CAShapeLayer *shapeLayer = [CAShapeLayer  layer];

 shapeLayer.path = path.CGPath;

 [self.view.layer addSublayer:shapeLayer];

  NSLog(@"-------viewDidlod-------");

}