代码很简单，一看便知。这里为顺时针，若想要逆时针，clockwise改为0，还需更改起始角度和终点角度。
源码地址：https://github.com/LfyDragon/CountDown
直接上代码：- (void)drawRect:(CGRect)rect {
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.frame = self.bounds;
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(self.frame.size.width/2, self.frame.size.height/2) radius:self.frame.size.height/2 startAngle:-M_PI_2 endAngle:M_PI*3/2 clockwise:1];
shapeLayer.path = path.CGPath;
shapeLayer.fillColor = [UIColor clearColor].CGColor;
shapeLayer.lineWidth = 10.0f;
if ([self.flag isEqualToString:@"track"]) {
shapeLayer.strokeColor = [UIColor colorWithRed:146/255.0f green:146/255.0f blue:146/255.0f alpha:1].CGColor;
} else{
shapeLayer.strokeColor = [UIColor colorWithRed:61/255.0f green:191/255.0f blue:135/255.0f alpha:1].CGColor;
}
//每个虚线长度为2，间隔为3 这句设置线条为虚线，去掉即为实线
], nil];
[self.layer addSublayer:shapeLayer];
if ([self.flag isEqualToString:@"process"]) {
CABasicAnimation *pathAnima = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
pathAnima.duration = self.time;
pathAnima.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
pathAnima.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnima.toValue = [NSNumber numberWithFloat:1.0f];
pathAnima.fillMode = kCAFillModeForwards;
pathAnima.removedOnCompletion = NO;
[shapeLayer addAnimation:pathAnima forKey:@"strokeEndAnimation"];
}
}
随手截个图：
