圆圈loader的动画

by 伍雪颖

github代码

- (void)awakeFromNib {

[self
setup];

[self
startAnimation];

}

- (void)setup {

self.backgroundColor
= [UIColor
clearColor];

self.backgroundLayer
= [CAShapeLayer
layer];

_backgroundLayer.strokeColor
= [UIColor
colorWithRed:0.129
green:0.455
blue:0.627
alpha:1.0].CGColor;

_backgroundLayer.fillColor
=
self.backgroundColor.CGColor;

_backgroundLayer.lineCap
=
kCALineCapRound;

_backgroundLayer.lineWidth
=
1;

[self.layer
addSublayer:_backgroundLayer];

}

- (void)startAnimation {

CGFloat
startAngle = - ((float)M_PI
/
2);

CGFloat
endAngle = (1.8f
* (float)M_PI) + startAngle;

UIBezierPath
*processBackgroundPath = [UIBezierPath
bezierPath];

processBackgroundPath.lineWidth
=
1;

[processBackgroundPath
addArcWithCenter:CGPointMake(self.bounds.size.width/2,
self.bounds.size.height/2)

radius:(self.bounds.size.width
-
1)/2

startAngle:startAngle

endAngle:endAngle

clockwise:YES];

_backgroundLayer.path
= processBackgroundPath.CGPath;

CABasicAnimation
*rotationAnimation = [CABasicAnimation
animationWithKeyPath:@"transform.rotation.z"];

rotationAnimation.toValue
= [NSNumber
numberWithFloat:M_PI
*
2.0];

rotationAnimation.duration
=
1;

rotationAnimation.cumulative
=
YES;

rotationAnimation.repeatCount
=
HUGE_VALF;

[_backgroundLayer
addAnimation:rotationAnimation
forKey:@"rotationAnimation"];

}

- (void)drawRect:(CGRect)rect {

_backgroundLayer.frame
=
self.bounds;

}