-(void)begigFlashAnimation {
  // 缩放 + 透明度动画
  self.flashView.transform = CGAffineTransformMakeScale(0.1, 0.1);
  [UIView animateWithDuration:3 animations:^{
    self.flashView.transform = CGAffineTransformMakeScale(1,1);
    self.flashView.alpha = 1.0;
    [UIView beginAnimations:@"flash" context:nil];
    [UIView setAnimationDuration:2];
    [UIView setAnimationCurve:UIViewAnimationCurveLinear];
    self.flashView.alpha = 0;
    [UIView commitAnimations];
  }];
}

- (CAAnimationGroup *)groups {
  if (!_groups) {
    // 缩放动画
    CABasicAnimation * scaleAnim = [CABasicAnimation animation];
    scaleAnim.keyPath = @"transform.scale";
    scaleAnim.fromValue = @0.1;
    scaleAnim.toValue = @1;
    scaleAnim.duration = 2;
    // 透明度动画
    CABasicAnimation *opacityAnim=[CABasicAnimation animationWithKeyPath:@"opacity"];
    opacityAnim.fromValue= @1;
    opacityAnim.toValue= @0.1;
    opacityAnim.duration= 2;
    // 创建动画组
    _groups =[CAAnimationGroup animation];
    _groups.animations = @[scaleAnim,opacityAnim];
    _groups.removedOnCompletion = NO;
    _groups.fillMode = kCAFillModeForwards;
    _groups.duration = 2;
    _groups.repeatCount = FLT_MAX;
  }
  return _groups;
}