画圆圈

画圆圈

by 伍雪颖

CGPoint CGRectGetCenter(CGRect rect){
    returnCGPointMake(CGRectGetMidX(rect),CGRectGetMidY(rect));
}
@interfaceViewController () {
    CAShapeLayer *circleLayer;
}
@property (nonatomic,strong)CADisplayLink *timer;
@end
@implementation ViewController

- (void)viewDidLoad {
    [superviewDidLoad];
    circleLayer = [CAShapeLayerlayer];
    CGFloat radius =30.0;
    UIBezierPath *path = [UIBezierPathbezierPathWithArcCenter:CGRectGetCenter(self.view.frame)
                                                        radius:radius
                                                    startAngle:-0.5 * M_PI
                                                      endAngle:1.5 * M_PI
                                                     clockwise:YES];
    circleLayer.path = path.CGPath;
    circleLayer.strokeColor = [UIColorredColor].CGColor;
    circleLayer.lineWidth =3;
    circleLayer.fillColor =nil;
    circleLayer.contentsScale = [UIScreenmainScreen].scale;
    [self.view.layeraddSublayer:circleLayer];
}