使用 shapeLayer 当动画层 其实以前有写过 类似的了
github: https://github.com/li6185377/AddScore
self.pregress = [[CAShapeLayer alloc]init];
_pregress.frame = CGRectMake(15,18, 64,64);
_pregress.lineWidth= 3;
_pregress.fillColor= [UIColor colorWithWhite:0 alpha:0].CGColor;
_pregress.strokeColor = RGBCOLOR(225,140,150).CGColor;
_pregress.lineCap = @"round";
_pregress.strokeStart = 0;
_pregress.strokeEnd = 0;
_pregress.path = CGPathCreateWithEllipseInRect(pregress_bg.bounds, NULL);
_pregress.transform = CATransform3DMakeRotation(M_PI, 0, 0, 1);
[self.layer addSublayer:_pregress];