iOS 开发之环形倒计时进度条（虚线／实线）

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

    shapeLayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:2], [NSNumber numberWithInt:3], 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：