UIView *circleView = [[UIView alloc]initWithFrame:CGRectMake(, , , )];

     shapeView.backgroundColor = [UIColor greenColor];

     [self.view addSubview:circleView];

     // 实现圆形进度条

     CAShapeLayer *shapeLayer =[CAShapeLayer layer];

     shapeLayer.frame = circleView.bounds;

     //绘制

     UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:circleView.bounds];

     shapeLayer.path = path.CGPath;

     // 设置填充颜色

     shapeLayer.fillColor = [UIColor greenColor].CGColor;

     // 设置线条宽度

     shapeLayer.lineWidth = 2.0f;

     // 设置线条颜色

     shapeLayer.strokeColor = [UIColor redColor].CGColor;

     [circleView.layer addSublayer:shapeLayer];

     // 设置基础动画

     CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

     pathAnimation.duration = 3.0;

     pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

     pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];

     pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];

     pathAnimation.fillMode = kCAFillModeForwards;

     pathAnimation.removedOnCompletion = NO;

     [shapeLayer addAnimation:pathAnimation forKey:@"strokeEndAnimation"];