CGFloat timeW = self.view.bounds.size.width;

timeAnimation * timean = [[timeAnimation alloc]initWithFrame:CGRectMake(,,timeW,timeW)];

    　timean.center = CGPointMake(self.view.bounds.size.width*0.5, self.view.bounds.size.height *0.5);

[self.view addSubview:timean];

#define PI 3.14159265358979323846

#define kradius self.bounds.size.width*0.1

-(instancetype)initWithFrame:(CGRect)frame

{

    if (self = [super initWithFrame:frame]) {

        self.frame = frame;

        self.backgroundColor = [UIColor clearColor];

    }

    return self;

}

- (void)drawRect:(CGRect)rect {

    CGContextRef context = UIGraphicsGetCurrentContext();

    [self greenRound:context];

    self.alpha = 0.5;

    [self test];

}

-(void)test

{

    // 2.创建缩放动画对象

    CABasicAnimation *scale = [CABasicAnimation animation];

    scale.keyPath = @"transform.scale";

    scale.fromValue =[NSNumber numberWithFloat:0.0];

    scale.toValue =[NSNumber numberWithFloat:1.0];

    CABasicAnimation *scale1 = [CABasicAnimation animation];

    scale1.keyPath = @"opacity";

    scale1.fromValue =[NSNumber numberWithFloat:1.0];

    scale1.toValue =[NSNumber numberWithFloat:0.0];

    // 4.将所有的动画添加到动画组中

    CAAnimationGroup *group = [CAAnimationGroup animation];

    group.animations = @[scale,scale1];

    group.duration =.;

    group.repeatCount = HUGE_VALF;

    group.removedOnCompletion = NO;

    group.fillMode = kCAFillModeForwards;

    [self.layer addAnimation:group forKey:nil];

}

/**画绿色的圆*/

-(void)greenRound:(CGContextRef)context

{

    CGContextSetRGBStrokeColor(context, /255.0, /255.0, /255.0, );//画笔线的颜色

    CGContextSetLineWidth(context, 4.0);//线的宽度

    // x,y为圆点坐标，radius半径，startAngle为开始的弧度，endAngle为 结束的弧度，clockwise 0为顺时针，1为逆时针。

    CGContextAddArc(context, self.bounds.size.width *0.5,self.bounds.size.height*0.5,self.bounds.size.width*0.21, , *PI, ); //添加一个圆

    CGContextDrawPath(context, kCGPathStroke); //绘制路径

}